SEVERITY OF ILLNESS IN THE NEONATE:
A CONCEPT ANALYSIS
Kimberley G- Salonen
A thesis submitted in conformity with the requirements
for the degree of Master of Science,
Graduate Department of NursUig Science,
University of Toronto
O Copyright by Kimberley G. Salonen, 2001
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ABSTRACT
Severity of m e s s in the Neonate:
A Concept Analysis
Master of Science
Graduate Department of Nursing Science
University of Toronto, 200 1.
Kimberley G. Salonen
Variability in the achievement of neonatal outcornes has been attributed partly to
severity of illness (SOI). SOI in the neonate has been dehed inconsistently and measures
may be inaccurate as a result. The purpose of this study was to develop a consistent
definition of the concept h m current neonatal literature. The objectives included
determinhg the attributes of SOI, examinhg the antecedents and consequences, identi f j h g
related concepts, and describing the uses in the literature. A sample of 71 articles was
obtained fkom a compter and manuai search of the literature fiom 1990 to 2000. The design
used was a concept analysis based on Rodgers' evolutionary view of concepts. The results
showed that SOI is characterized primady by instability that is measured in the
physiological domain. Other attributes, suffering and disability were also identified. This
study offers a beguining understanding of the concept and contributes to identiwg,
assessing and using SOI in clinical nursing practice.
ACKNOWLEDGMENTS
1 would like to extend my sincere thanks to my thesis supervisor, Dr. Bonnie Stevens
for her thoughtful contributions, guidance and support thughout the research process.
A~so, 1 would like to thank the members of my thesis cornmittee, Dr. Patricia Petryshen and
Dr. Souraya Sidani for their expertise and valuable contributions to the development of this
thesis. A special thanks goes to Dr. Patricia McKeever for her early thought-provoking input
and to Dr. Donna Wells, as my fourth reader. I wish to thank Sharyn Gibbins and Brenda
Stade for their technical support.
1 wish to extend my appreciation and special thanks to Dr. Gai1 Donner and Dr. Linda
McGillis-Hall and to my classmates, Sherri Belton, Karen Ray and Tracey Tully for the
support and encouragement they have offered to me throughout my experience as a graduate
student.
1 wish to acknowledge and thank the Heart and Stroke Foundation of Ontario, the
Hospital for Sick Children, and the University of Toronto for scholarships that have
supported me in my studies as a graduate student at the Faculty of Nursing Science,
University of Toronto.
Finally, 1 would like to thank my family and niends for their unwavering
encouragement, understanding and support during this process. A big than. you goes to my
children @ana and Erin), rny mother and my sister. A very special thanks goes to my
husband whose insights, support, and inspiration has helped make dreams come true. 1
would like to dedicate this thesis in loving memory of my father, Lander Harrison.
TABLE OF CONTENTS
- - Abstract ....................................................................................... II
* *. Acknowledgments ........................................................................... III
Table of Contents.. .......................................................................... iv
List of Tables.. ............................................................................... vii
--- List of Figures,. ............................................................................... v u
List of Appendices.. ......................................................................... ix
CHAPTER 1: THE PROBLEM
Background and Significance.. ..................... .. ............................... 1
Problem. ............................................................................. .--5
- - Purpose and Objectives. ............................................................ ..5
Li terature Review ..................................................................... .5
Conceptual Foundations for the Study, ........................................... .10
........................................... S u m m q of Conceptual Foundations.. -14
CHAPTER 11: METHODS AND PROCEDURES
.................................................................... Research Design. .16
............................. Concept Analysis as a Method of Inqiiity.. 16
....................................................... Critique of Methods.. 17
.......................................... S ~ ~ l l ~ l l a r y of Research Design.. -22
............................................................ Selection of the Sample.. 24
. . ......................................................... Selection Cntena.. .25
................................................................ Procedures.. ..26
....................................................................... Data Collection 28
.................................................................... Data Management 31
...................................................................... Records -31
......................................................................... Rigor -32
........................................................... Data Analysis Procedures 33
Selection of the Sample .................................................... 33
Description of the Sample ................................................. 33
Analysis of the Concept .................................................... 34
CHAPTER III: RESULTS
.................................................................... Verification Tests 35
.............................................................. Selection of the Sample 36
........................................................... Description of the Sample 39
Author, Patient and Setting Types ........................................ 39
............................................... Publications: Type and Year 40
.................................................................... Measures -42
............................................................ Surrogate Terms -44
................................................ Definitions of the Concept -46
........................................................... Analysis of the Concept -46
........................ Dennition of Severity of m e s s in the Neonate 46
.................................................................... Attributes 48
............................................................ Other Attributes 50
................................................................ Antecedents -50
............................................................... Consequences 53
Related Factors ............................................................. -54
Uses .......................................................................... -57
. . Empmcal Examples.. ................................................... - 3 9
C W T E R IV: DISCUSSION
. . Descnpt~on of the Sample ...................................................... .. . -61
. . Major Study Fmdmgs .............................................................. -63
Other Issues. ......................................................................... 72
Verification Tests .......................................................... 72
Lack of Definitions of the Concept in the Literature. ..... .. ......... -73
............................. Declining Number of Publications in 2000 74
............................................. Subgroups Among Neonates 75
.......................................... Neonates, Children and Adults -75
Empirical Examples ........................................................ 75
.................................................................... Measures 76
CHAPTER V: SUMMARY, IMPLICATIONS, AND CONCLUSIONS
Summary ............................................................................. 78
Implications ......................................................................... -79
.......................................................... Conceptual Model 79
................................................. Clinical Nursing Practice -81
..................................................................... Research 86
Conclusions ........................................................................ -87
REFERENCES ............................................................................. -89
LIST OF TABLES
Table 1 .
Table 2 .
Table 3 .
Table 4 .
Relative Frequency Distribution of Author Types ............. 39
Relative Frequency Distribution of Patient types ............... 40
Relative Frequency Distribution for Publication Type ......... 41
Surrogate Terms for SOI in the Neonate ......................... 45
vii
Figure 1 .
Figure 2 .
Figure 3 .
Figure 4 .
LIST OF FIGURES
Schema of Sample Selection ............................................... 37
Frequency Distribution by the Year of Pubiication ..................... 41
....... Frequency Distribution of the Use of Neonatal SOI Measures 4 3
Conceptual Mode1 of Severity of Illness. ..................... .. .. ... .... 47
LIST OF APPENDICES
Appendix A .
Appendix B .
Appendix C .
Appendix D .
Appendix E .
Appendix F .
Appendix G .
Critique of Concept Analysis Methods ................. 105
Cornputer Database Search ............................... 107
Record Book Sample ...................................... 108
Data Collection Form ..........~........................... 110
RZference List of IneligibIe Articles ..................... 111
Measures and Indicators of Severity of Illness ......... 123
Composite Measures of Severity of Illness ............ .126
CHAPTER ONE
The Problem
Severity of iiiness (SOI) has been identified as a characteristic of the neonate that c m
influence neonatal outcomes. To determine the effectivmess of interventions in neonatal
care and to predict the consequences of care, sources of variability must be identined and
controlled in neonatal outcomes research. SOI is a concept important to neonatal care as it
contributes to variability in achieving neonatal outcomes, different from traditional neonatal
nsk factors such as birth weight and gestational age. Although mimy measures of SOI in the
neonate exist, these measures have been developed using diverse dennitions of the concept.
As a result, operational definitions and indicators have varied widely. Also, p r h q
measures of SOI in the neonate have been derived fiom pediatric and adult SOI measures.
This rnay have resulted in the development of neonatal mesures of SOI that do not
specifically reflect the neonatal population, as the definition of the concept and the measure
were originally developed for children and adults. Inconsistencies in the way that SOI is
defined have made it difficult to identify and understand the meaning of the concept in the
neonatal population. A clear definition of SOI is required to produce precise and consistent
rneasures and, therefore, accurate results of neonatal outcomes studies. In this thesis, the
analysis of the concept of SOI in the neonatal population is the major focus.
Background and Simu'ficance
Preterm and sick neonates are requiring more financial and human resources as
survival rates increase. There has been an increased interest in measuring outcomes of a
clinical, economic and administrative nature to better manage resources (Petryshen, O'Brien
Pallas, Sc Shamian, 1995). The measurement of neonatal outcomes has received increasing
attention among researchers, managers and clinicians in health-related disciplines including
nursing (Holrnsgaard & Petersen, 1996; Long & Soderstrom, 1995; Petryshen & Stevens,
1995; Schraeder, Heverley, & O'Brien, 1996; Stevens, Petryshen, Hawkins, Smith & Taylor,
1 996; Thigpen, 1988). Researchers have examined traditional risk factors such as gestational
age and birth weight in an effort to understand variability in the achievement of neonatal
outcomes (Holrnsgaard & Petersen, 1996; International Neonatal Network @NN-J, 1993;
Richardson, Gray, iMcCormick, Workman & Goldmann, 1993; Schraeder et ai., 1996).
Variability in outcomes can be explained in part by these nsk factors (Hack et al., 1991).
SOI has been identified as a potentially important independent source of variability in the
achievement of neonatai outcomes (INN, 1993; Richardson, Gray, McConnick, et al., 1993).
Nurses make clinical decisions and provide care or interventions that are intended to
make a change in the condition or outcome of the neonate (Donabedian, 1988; Hegyvary,
1991 ; Marek, 1989; Mitchell, 1993). Clarification of the concept SOI in the neonate is
necessary to find out: (a) whether the concept is identifiable in neonatal nursing practice
(Chinn & Kramer, 1991; Walker & Avant, 1995), (b) how the concept might be used in
practice, research and theoretical models of neonatal care (Rodgers, 1993a) and (c) the
significance of the concept to neonatology in general (Rodgers, 1993a).
Developing a dennition of the concept SOI can provide the basis for the development
of an operational definition, selection of appropnate indicators and the development of valid
instruments (Noms, 1982). Accurate measurement of SOI will allow nurses to investigate
the nature of the relationship between SOI in the neonate, nursing interventions and
outcomes. Identimg factors that relate to neonatal nursing care and conducting research
that relates directly to clinical practice may facilitate the development of evidence-based
practice in the care of nmnates.
As SOI is a potentially signincant determinant of neonatal outcornes, it is important
to have a clear definition of the concept. Few definitions of the concept of SOI exist in the
neonatal literature- Diverse perspectives about the dimensions of SOI in the neonate have
been discussed in articles for example; physiologie stability (Richardson, Gray, McCormick,
et al., 1993; Yeh, Pollock, Ruttiman, Holbrook & Fields, 1984), therapeutic intensity (Gray,
Richardson, McCormick, Workman-Daniels & Goldmann, 1992) and suffering and disabiiity
(Almeida & Persson, 1998). Most commonly, definitions of SOI in the neonate have been
derived fiom pediatric and adult populations (Cuiien, Civetta, Briggs & Ferrara, 1974;
Knaus, Zimmerman, Wagner, Draper & Lawrence, 1981; Pollock, Ruttiman & Getson, 1988;
Yeh et al., 1984) and are not made explicit in neonatal measures (Georgieff, Mills & Bhatt;
1989; Gray, Richardson, McConnick, Workman-Daniels, et ai., 1992; Richardson, Gray,
McCormick, et al., 1993). The definitions of SOI are generaiiy inconsistent and diverse, and
those dehitions borrowed fiom pediatric and adult measures do not reflect neonatal
characteristics. A clear definition of the concept is a necessary f h t step to the development
of consistent, accurate measures of SOI-
Operational definitions of SOI measures differ significantly in terms of the type and
number of dimensions of the concept they capture because the concept has been defined
inconsistently. Proxy measures of SOI in the neonate have been commonly used, such as
biah weight, gestational age, fÎequency of invasive procedures and therapy use (Gray,
Richardson, McCormick, Worban-Daniels, et al., 1992; Johnston, Stevens, Yang & Horton,
1996; Minde, Whitelaw, Brown & Fitzhardinge, 1983). Leading neonatal SOI measures
have been derived fiom pediatric and adult measures and therefore, may not reflect neonatal
charactens tics (Georgieff et al., 1 989; Gray, Richardson, McConnick, Worhan-Daniels, et
al., 1 992; Richardson, Gray, McCormick, et al., 1993). A h , SOI measures use a variety of
indicators to measure the concept that range nom univariate approaches, such as length of
hospital stay and mortality (Lee, Perlman, Ballantyne, Elliott, & To, 1995) to complex
approaches incorporating many dimensions, such as complications and therapies (Gray,
Richardson, McCormick, Workman-Daniels, et al., 1992; Minde et al., 1983). Many
inconsistencies exist among measures of SOI. The development of consistent, accurate
measures of SOI is reliant on the deveiopment of a clear definition of SOI,
Unclear, diverse definitions of the concept SOI, including definitions denved nom
children and adults, have contributed to dficuities in understanding the meaning of the
concept and wide variation in operational definitions and indicators, The lack of consistency
in measurernent of SOI makes it very difficult to accurately measure this source of variability
in neonatal outcornes studies. At the time of this analysis, no systematic revïew of the
concept was found that specifically analyzed the concept of SOI in the neonate.
Problem
Current definitions of SOI in the neonate may fail to provide an accurate definition of
the concept and to capture characteristics of the neonate that are different h m children and
adults: (a) SOI has been inconsistently defined in the neonatal literature, (b) some measures
of SOI in the neonate have been derived fiom pediatric and adult measures without
consideration of potential ciifferences between the populations.
Purpose and Objectives
The overall purpose of this analysis was to develop a definition of SOI in the neonate
that captures neonatal characteristics and reflects a consistent view of the concept derived
fkom current neonatal literature. This study addressed the following research objectives:
1. To determine the essential attributes of SOI.
2. To examine the antecedents and consequences of SOI.
3. To ident* concepts related to SOI.
4. To describe the uses of SOI in the literatwe.
Literature Review
Histoncally, the concept of SOI has reflected a traditional 'medical' perspective in
answering the question 'How sick is the individual?'. The Shorter Oxford Enghsh
Dictionary on Historical Principles (1968) identified the first recorded use of the term by
physicians as dating in the late 1800s. Measures of SOI in health sciences have proliferated
mostly since the 1970s, beginning with adult measures. This review of the literature focused
on the evolution of leading neonatal measures of SOI that have been derived from pediatric
and adult measures. Other neonatal measures of SOI appeared idkequently in the literature
and were not clearly derived fkom other measures or definitions of the concept. This
exploration of the conceptual origins of the leading neonatal measures of SOI identifieci: (a)
definitions derived fkom adults and children that have heavily influenced the development of
the concept and (b) issues associated with appiying derived definitions of SOI to neonates.
Adult measures have employ,-d several appmaches to measuring SOI including
diagnostic, disease specific, therapeutic intensity, and mute physiology (Culien et ai., 1974;
Hom et al., 1985; Knaus et al., 198 1 ; Teasdde & Jennett, 1974). The diagnostic approach to
m e a s d g SOI classified SOI on the basis of specific medical diagnoses and procedures such
as Diagnosis Related Groups (DRGs) (Hom et al., 1985; Richardson & Tamow-Mordi,
L994). Disease specific measures of SOI included indicators such as symptoms, physical
hdings, events and patient characteristics known to be associated with outcornes of the
disease such as survival or specific rnorbidities. Examples of these measures included
trauma scores, cardiac scores, and bum scores (Teasdale & Jemet, 1974; Teres, Lemeshow,
Avninin & Pastides, 1987; Wheeler, Van Harrison, Wolfe & Payne, 2983). Therapeutic
intensity measures such as the Therapeutic Intervention S c o ~ g System (TISS) assessed
therapy use to reflect SOI (CuUen et al., 1974; Richardson & Tamow-Mordi, 1994). TISS
was introduced in 1974 and is considered a well-used indirect measure having many
applications for classif$ng patients including (a) detennining SOI, (b) establishing
nurse:patient ratios, (c) assessing current utilization of hospital beds, and (d) establishing
future needs of intensive care unit beds (Keene & Cuilen, 1983). The acute physiology
approach revolved around the idea that distwbed physiology meant a more iU neonate
(Richardson & Tamow-Mordi, 1994). The Acute Physiology and Chronic Health Evaluation
(APACHE), was the first widely accepted measure of SOI for adults (Knaus et al., 1981). It
was based on the assessrnent of probability of mortality and was identified to be a SOI index
(Knaus et al., 1981). The APACHE was intendeci to classifjr groups of patients and to
represent acute illness in hospitalized patients (Knaus et al., 1981). The measure was
primarily physiology-based including 34 physiological measures fiom seven organ systems.
Also, additional points were added for age and chronic health status.
These four approaches to assessing SOI were based on diverse assumptions, ideas,
indicators, measures and uses. Dehitions of SOI as a concept were not apparent in these
adult measures. The evolution of these measures has focused on reducing the number of
indicators, simplimg the evaluation of SOI and maintaining predictive power (Richardson
& Tarnow-Mordi, 1994).
In pediatric practice, the leading measures of SOI have evolved £rom the APACHE
(Knaus et al., 1981)- The Physiologic Stability Index (PSI), developed by Yeh et al. in 1984,
was the first to be denved from the APACHE (Knaus et ai., 1981). The PSI measure was
used primarily to assess severity of acute illness in the general pediatric intensive care
population (Yeh et al., 1984). The PSI measure was physiology-based and also relied on the
same number of variables (34) fiom seven physiologic systems as the APACHE (Knaus et
al., 198 1). The authors described their method as, ". . directly assess[ing] severity of illness
by quantitating physiologic stability9'(Yeh et al., 1984, p. 445). Adjustments were made to
the normal ranges for physiological indicators to accommodate dinèrences in children. Yeh
et al. (1 984) made reference to other differences that existed between the cbild and the adult,
such as the fact that children are actively growing. An explicit definition of the concept was
not discussed in the Yeh et al. article (1984). Also, dimensions or indicators that might be
unique to children were not identified. The pediatric measure that was developed
imrnediately after PSI was called the Pediatric Risk of Mortality Score (PRISM) (Pollock et
al., 1988)- The PRISM was derived h m the PSI to reduce the number of physiologic
variables required for pediatric mortality nsk assessrnent (Pollock et al., 1988). The
conceptual origin of the PSI was discussed in greater detail in the development of the PRISM
rneasure than in the original PSI article. The basis for the PSI was the hypothesis that
physiologic instability directly reflects mortality risk (Poilock et al., 1988). Because existing
SOI measures were sparse and indirect, various combinations of measures were used to
validate these new instruments.
In neonatology, the leading SOI measures were also derived fiom the PSI and
APACHE. The first neonatal measure was an adapted version of the PSI (Georgieff et al.,
1989). The normal ranges of variables were adjusted to reflect neonatal physiology without
consideration of potential Merences in the characteristics among neonates, children and
adults. Following use of the adapted PSI, the Score for Neonatal Acute Physiology (SNAP)
was developed (Richardson, Gray, McComiick, et al., 1993). The authors of SNAP
suggested that few appropriate measures of SOI existed for neonates. Richardson, Gray,
McComiick, et al. (1993) identified that adjustment using birth weight, sex and race were
insacient to reconcile variations among neonatal outcornes. Physiology-based approaches
used by pediatric and addt physicians were recognized as having potential for the
measurement of SOI in neonates (Richardson, Gray, McCormick, et al., 1993). The SNAP
was developed for neonates using physiologic ïndicators and measuring, the degree of
derangement fiom physiologic normal (Richardson, Gray, McCormick, et al., 1993). The use
of physiological derangements in SNAP was similar to the PSI and the APACHE (Knaus et
al., 198 1 ; Richardson, Gray, McComick, et al., 1993; Yeh et al., 1984). The SNAP authors
identified that neonates had major differences in physiology in cornparison to children
(Richardson, Gray, McCormick, et al., 1993). They identïfïed that low birth weight and
immaturity were key differences between the two populations. Other examples of
differences in the characteristics of neonatal and pediatric populations included a disparate
amount of trama, the fiequency and varïety of congenital anomalies and the need for
chronic prolonged hospital admission to mature (Richardson, Gray, McCorrnick, et ai.,
1993). Although Richardson, Gray, McCormick, et al., 1993, identified numerous
differences between neonates and children, it was not clear how the definition of the concept
and the choice of indicators were changed to address these dineremes. Actual changes made
by Richardson and colleagues to develop the SNAP measure included the removd of 13
items, addition of 5 items, adjustment to the ranges of physiologic indicators, and alteration
of item weighting based on consultation with a panel of experts (Richardson & Tamow-
Mordi, 1994).
Other leading neonatal measures of SOI included the Neonatal Therapeutic
Intervention Scoring S ystem (M'ISS) (Gray, Richardson, McCormick, Workman-Daniels, et
al., 1992) and the CLinical Risk Index for Babies (CRIB) (INN, 1993). NTISS, a therapeutic
intensity index for neonates, was designed to indirectly measure SOI regarding therapy use
(Gray, Richardson, McComiick, Workman-Daniels, et al., 1992). The NTISS measure was
derived directly fiom the adult measure, TES, (Cullen et al., 1974; Gray, Richardson,
McCormick, Workman-Daniels, et al., 1992). Another leading neonatal measure was the
CRIB that was designed specifically to predict death (INN, 1993; Tamow-Mordi et al.,
1990). This score was constnicted similariy to the PRISM score in pediatrics although the
content was somewhat different (Pollock et al., 1988). The CRIB incorporatecl more diverse
indicators including physiologic, congenital anomalies, birth weight and gestational age that
appeared to be more sensitive to the differences of neonates (INN, 1993). Explicit
definitions of the concept were rare and often non-existent in these adult, pediatric and
neonatal measures. It was much more common for SOI to be describeci or discussed in terms
of its components or indicators in the literature than de- at the theoretical level.
As explicit dennitions of the concept SOI are rare and measures of SOI Vary widely
in the literature, current understanding of the concept is incomplete. Logicaliy, neonatal,
pediatric and adult populations do no share the same characteristics and therefore dimensions
of the concept may ciiffer among them. Authors of neonatal SOI measures have identified
specific neonatal charactenstics that set the neonate apart fiom the other populations
(Richardson, Gray, McCormïck, et al., 1993). Neonatal development is characterized by
rapidly developing physiological processes, neurological organization, and behavioural
responses (Richardson, Gray, McCormick, et al., 1993). Issues related to maturation and
rapid development are unique to the neonate. Neonatal researchers rely heavily on the
measurement of birth weight and gestational age to reflect neonatal charactenstics
(maturation). Birth weight and gestational age can Vary widely within the neonatal
population. They are recognized in neonatology as indicators of vulnerability and c m predict
poor neonatal outcornes. Birth weight and gestational age are fcequently used as risk factors
in neonatal research (INN, 1993). These characteristics are unique to neonates and are not
shared with children and adults. As a result, dimensions of the concept of SOI may be
different in neonates than in children and adults.
Conceptual Foundations for the Study
This section on conceptual foundations wiii serve to: (a) outline two primary schools
of thought, entity and dispositional, and how the ideas have d u e n c d current thinking about
concepts; (b) outline the characteristics of concepts as they have been defhed by nurse
authors and identm similarities that exist among the different viewpoints; and (c) descnbe
the evolutionary view and identifjr features of this view that will provide the basis for
methodological decision making in this study.
The entity view (Aristotle, 1947) has dominated the evolution of concept analysis.
Within this view, a concept is dehned as an entity or 'thing' that matches an element of reality
such as objects, ideas or words (Rodgers, 1993b). The 'essence' of the concept is considered
to be a universal law that is not influenced by changes in the world (Aristotle, 1947). Irnplicit
in this view is the idea that the critical attributes, representing the essence of the concept, are
unchanging (Rodgers, 1993b). Therefore, a precise unchangîng definition of the concept cm
be achieved and can be applied to al1 situations.
The dispositional theones of concepts purport that the development of a concept is
dependent on its use, influenced by the habits and abilities of the person using the concept
(Rodgers, 1993b). Wittgenstein (1968) focused his later writings on the use of concepts as
detenninants of their meaning- Ryle identified that concepts are integrally related to ow
ability to perform tasks such as the effective use of Ianguage such as, 'What were we unable
to do until we had acquired it [the concept]?" (1971, p. 448). These ideas innuenced the
development of other views in psychology but retained the primary features that; (a)
concepts do not have rigid boundaries, and (b) necessary and suflicient conditions are not
required for the concept to exist (Rodgers, 1993b). In this philosophical view, de£ïning
attributes must demonstrate some degree of association with the concept. Not al1 examples
of the concept illustrate equally what the concept (the category defined by attributes) is.
Whether a particular example of the concept falls within the category is detennined by the
degree of fit of attributes between the example and the concept (category) (Morse, 1995).
This view supports the idea of relativism wherein concepts are not ngid or static and are
influenced by use (Morse, 1995). Also, examples of the concept demonstrate relative
associations with the category that is the concept (Morse, 1995).
Contemporary philosophers such as Toiilmin (1972) considered the influence of
social factors in the development of concepts used in science and emphasized the relationship
between concepts and scientinc progress. When a society uses or takes ownership of a
concept, the concepts of interest that have importance in society or solve society's problems
are progressed. Concepts are developi through the process of "enculturation" through
imitation, interaction or education according to Toulmin (1972). Therefore, concepts are
context-dependent, (Le. influenced by the social context surrounding the use of the concept).
Also, concepts change over t h e based on usage, importance and ability to solve problems
(Rodgers, 1993b). Thus, content and explanatory power of the concept is infiuenced and
changed by its continual use and ongoing critical analysis (Rodgers, 1993b).
Rodgers (1 993a) conceived the process of concept development as a cycle. Her
evolutionary view characterized concepts as having a dynamic nature that changed with tirne
and context and were not bound by a specific 'essence'. Sipificance, use and application of
the concept influenced concepts in that they acquired meaning and thus evolved (Rodgers,
1993a). For example, concepts were used to solve problems and characterize phenornena
that, in hun, increased their use and fiuther enhanced concept development. Therefore, use is
important in defining a concept. Increased use leads to broader application and the discovery
of strengths and limitations (Rodgers, 1993a).
This approach to concept analysis was usehù in mfining and clarifying concepts of
interest to nurses. Complex nursing phemmena related to human beings required the use of
concepts that could not be separateci from context, time or nature ofthe problem (Rodgers,
1993a). Problems were addressed by considering multiple and related factors. .Therefore,
nursing requires methods that consider and incorporate these influencing factors to develop
definitions of concepts usefiil to the profession.
Concepts most commonly are identified as the building blocks of theory (Morse,
1995). Nurse authors, however, have approached concepts fiom a number of different
perspectives (Rodgers, 1993a). Concepts have been linked to ernpirical reality when the
concept is represented by a thing, object, property, or word (Becker, 1983; Hardy, 1974;
Jacox, 1974; Keck, 1986; Kim, 1983; Walker & Avant, 1988). Other authors have focused
on cognitive activities that are associated with concepts, such as idea formation, abstraction,
and perception (King, 1988; Meleis, 1985; Watson, 1979). Also, language, as reflected by
meaning, usage and communication, was identined as important to the development of
concepts @uldt & Giffin, 1985; Tadd & Chadwick, 1989). These perspectives contributed to
our understanding of concepts and also illustrated the complexity of concepts and explained
the existence of a number of different approaches to analysis. Rodgers (1 993b) identified
that, despite the diversity of opinion, some commonality exists. "There is a consensus that
concepts are cognitive in nature and that they are comprised of attributes abstracted Çom
reality, expressed in some fom and utilized for some common purpose" (Rodgers, 1993b,
p.3 0). Nurse researchers who have developed methods of concept analysis generally agreed
that meaning of a concept was developed through use and that the identification of the
concept's essential attributes contributed to a greater understanding of the nature of the
concept (Chin. & Kramer, 1991; Noms, 1982; Rodgers, 1993a; Schwartz-Barcott & Kim,
1993; Walker & Avant, 1995).
An examination of philosophicai views provided the theoretical basis for
understanding how a concept develops, the method chosen to anaiyze a particular concept
and the product' of concept analysis (Rodgers, 1993a; 1993b). The evolutionary view
(Rodgers, 1993 a; Rodgers, 1993 b) served as the h e w o d c for methodological decision
making in this study. The evolutionary view purports that a concept (a) does not have rigid
boundaries, (b) is context-dependent, (c) is tirne-dependent, (d) is developed based on how
usefül it is to the discipline, (e) applies activities of concept analysis based on the nature of
the problem, and (f) is judged on how weii it solves problems important to the profession
(Rodgers, 1 993a; 1 993b). The 'product' of concept analysis, based on this philosophical
view, provided essential attributes that reflected current use, significance and application of
the concept within a given discipline (Rodgers, 1993a).
Summary of Conceptual Foundations
Two schools of thought, entity and dispositional, dominated theories of concepts
(Aristotle, 1947; Ryle, 197 1; Toulmin, 1972; Wittgenstein, 1968). Although these theories
are quite different, they are not clearly divisible, "Often, there are considerable areas of
overlap, and characterization of a particular viewpoint c m be based only on the author's
pnmary emphasis." (Rodgers, 1993b, p. 11). Additional ideas of concepts have evolved
including Toulmin's (1972) thoughts on the importance of the concept to society and how
concepts develop over thne based on context, use and ability to solve problems. Rodger's
(1993a) evolutionary view also considered context, time and nature of the problem to be
important to concept development, particularIy in relation to complex nursing phenomena.
M~dtiple ideas about the nature of concepts exist within the disciplirie of nursing.
Despite diversity of opinion among nurse authors, some commonality exists including that
the meaning of a concept is developed through use and that identification of essential
attributes help our understanding of the concept. Rodger's (1993a) evolutionary view was
chosen to guide methodological decision making for this study based on its congruence with
the characteristics of complex nursing phenornena in tenus of its sensitivity to context, time,
disciphne, usefulness, nature of the problem and ability to solve problems. The conceptual
foundation, nature of the concept SOI, purpose and objectives of the study guided the
sclection of the research design.
CHAPTERTWO
Methods and Procedures
Research Design
Concept aualysis was selected to be the research design for this study. Five methods
of concept analysis, developed in the discipline of nursing, were identined, reviewed and
critiqued for the purpose of selecting a design that was congruent with the purpose and
objectives of this study. The methods reviewed included (a) Walker & Avant (1995), (b)
Chinu & Kramer (199 l), (c) Noms (1982), (d) Schwartz-Barcott & Kim (1993), and (e)
Rodgers (1993a). A common goal shared by most methods of concept analysis was to
identie the essential attributes of a concept and to use the attributes to develop a definition of
the concept, This goal was congruent generally with the study purpose and objectives and
supported the use of concept analysis for the research design. The focus of this section was to
describe concept analysis as a research design and to select an appropnate methodology.
Concept Analysis as a Method of Inquiry
Concept analysis is one of the prirnary methods used to synthesize hwledge (Knd
& Deatrick, 1993). A number of researchers have developed approaches to concept analysis
within the discipline of nursing including, Walker & Avant (1 999, Chinn & Kramer (1 99 l),
Noms (1982), Schwartz-Barcott & Kim (1986), and Rodgers (1993a). Each researcher
employed a sornewhat Werent approach to analyzïng concepts, based on the purpose and
particular philosophical view. Although a clear procedure was identified in each of the
methods, the philosophical origins are less clear and more difficult to discem. Incorporating
more than one philosophical view was common among methods of concept analysis despite
philosophical views regarding the nature and development of concepts have evolved and
produced distinctly difEerent ideas about concepts (Rodgers, 1993 b).
Concept analysis generally involved i d e n t m g the essential amibutes of a concept
£kom the literature, foliowed by the development of a definition of the concept. Each method
of concept analysis included additional procedures that provided further information about
the concept, such as case exarnples (Walker & Avant, 1995). Additional procedures were
intended to address other goals of the methods such as (a) to develop an operational
definition and to measure the concept, (b) to develop theory, and (c) to integrate the literature
review with empirical data (Noms, 1982; Rodgers, 1993a; Schwartz-Barcott & Kim, 1993;
Walker & Avant, 1995).
Each method involved completion of a series of procedures or phases. Although
ordered steps were identified, most of the methods suggested the process of analyzing a
concept is iterative. The steps were not to be followed in a specific order (Rodgers, 1993a;
Walker & Avant 1995). Also, the methods required an inductive approach to reasoning
whereby a set of essential attributes was developed fiom the Iiterature- Essential attributes
were specifically identified or iderred fiom the literature depending on how the concept was
presented. Authors made inferences about the nature of the concept fkom the particular
definitions, exarnples, dimensions, and indicators they discussed and used in their work.
Critique of Methods
Five methods of concept analysis currently used in nursing were critiqued to
determine their usefulness in analyzing the concept of SOI in the neonate: Walker & Avant
(1 999, Chinn & Kramer (1 99 l), Norris (1982), Schwartz-Barcott & Kim (1 993) and
Rodgers (1993a). The methods were reviewed and the following aspects of each method are
summarized in Appendix A: (a) background (why the method was developed), (b) definition
of a concept (the approach to denning concepts chosen by the authon), (c) philosophical
view @sis for the development of the method), (d) primary purpose of the method, (e)
secondary goals, and (f) steps of the method. In addition, the rnethods were critiqued for
strengths and weaknesses and are sumrnarized in Appendix A. The following paragraphs
offer a concise critique of each method and identiw the research design chosen for this study.
Walker and Avant. The Walker and Avant (1995) method has been widely used in
nursing to analyze concepts. The analysis was based on an examination of the linguistic use
of the word and its charactenstics in the literahue. The philosophical origin of the method of
concept analysis developed by Walker and Avant (1995) was attributed to Wilson (1963).
Wilson (1 963) was concerned primarily with word use and the criteria and principles wherein
a precise conceptual definition is achieved, implying that concepts are static in nature. Once
discovered, the definition of a concept became universal and was therefore unchanging.
These ideas were not congruent philosophically with Walker and Avant's (1995) recent
assertion that the determination of essential attributes was iduenced by the context and t h e
when the concept was used. Although the philosophical perspective of the authors was
evident in a discussion of the method, context and tirne were not specifically included in the
procedure. None of the steps implied that data on conditions or context should be gathered.
Walker and Avant's (1995) method described an eight-step procedure that provided a clear
direction for the concept analysis. Although the process was outlined as a series of steps, the
authors described the approach as iterative. In addition to identimg uses and essential
attributes, Walker and Avant (1995) constructed examples for the purpose of fùrther
c lar img the concept. The use of examples to determine what the concept is and what it is
not contributed significantly to our understanding of the concept. The construction of
artificial examples however, could lead potentiaiiy to researcher bias in developing cases.
The identification of empirîcal referents was useful in developing an operational definition
and instrument- This particular step was beyond the scope of this concept analysis. Waiker
and Avant's (1995) purpose and method of concept analysis was generaiiy congruent with the
goals of this study.
Chinn and Kramer. Chinn and Kramer (1 99 1) derived their method fiom Wilson
(1963) and Walker and Avant (1988). Wilson's (1963 method of concept analysis is based
on the premise that concepts are static and unchanging. The description of the results of the
concept analysis by Chinn and Kramer (199 1) as being 'tentative and guiding in naturef
indicated a belief that a variety of factors inauenced the results of the analysis, which is in
contrast to Wilson (1 963). Chiun and Kramer (199 1) discussed the importance of social
context and values in andyzing concepts and included this type of data in the method. The
purpose of this method was to produce a tentative definition of the concept. Although
congruent with the aims of this concept anaiysis, the purpose was unifocal and the
description of the steps provided minimal direction for applying the method. The problem of
researcher bias in the use of constmcted examples was the same as in the Walker and Avant
method (1995)- This method contributed little information beyond what was presented by
Wallcer and Avant (1995).
Norris. The Noms (1 982) method of concept analysis was directed at the
development of meaningfiil descriptions of phenornena important to nursing for the purpose
of constmcting and testing theory. Meaningful descriptions contributed to the development
of concepts. Theory construction did not specincaily fit the goals of this concept analysis.
Noms (1982) stated that a concept can be precisely defineci, but did not discuss the
philosophical basis for the method in suEcient detail. Also, the influence of context and
time on the product of concept analysis was not discussed, yet the method incorporated
participant observation techniques. Valuable descriptive data about the concept as it existed
in context was extracted using this method. The philosophical basis for anaiyzing concepts
was unclear. Although there were five succinct steps, the method was difficult to apply
without more information to guide the process (Lackey, 1993). The method was primarily
centered on observation and description of the phenomenon, systematizuig the results, and
developing an operational definition and mode1 to develop hypotheses. The method was
most effective when applied to more observable phenornena (Lackey, 1993). The participant
observation approach, although contributing significantly to the anaiysis of a concept in a
specific context, was not feasible within the time h u e of this thesis work.
Schwartz-Bzcott and Kim. Schwartz-Barcott and Kim (1993) developed a method of
concept analysis to teach students how to seIect, develop and apply concepts and theoretical
frameworks in specific clinical nursing situations. The main purpose of the analysis was to
solve conceptual problems regading dennitions and measurement by refining individual
concepts. This purpose was congruent with the goals of concept analysis identified in this
study. The method incorporated three phases, theoretical, fietdwork and analytical. The
literature review conducted in the theoretical phase, focused on the discovery of meaning and
measurement issues. The goal of this phase was to produce essential attributes of a concept
and a working definition. Although the purpose of the method is clear, Schwartz-Barcott and
Kim (1993) did not describe adequately, the philosophical basis for the method or how the
authors they referenced contributed to the development of the philosophical underpiniiings
they used. The first phase was intended to discover broad uses and definitions to iden-
conceptual and measurement issues. Although a working dennition was produced, there was
a concem that the selection of a definition in chis phase may be premature and prevent the
researcher fiom being open to other possible essential attributes, The second phase involved
observation of the phenornenon in the field and the third phase was used to integrate the
results of the literature review with empirical data gathered fiom the field. The second and
third phases were considered beyond the scope of the present shidy.
Schwartz-Barcott & Kim (1993) agreed with Rogers (1993a) and Walker & Avant
(1995) regarding the use of existing literature as the bais for ident-g essentiai attriiutes.
They extended this examination ofthe concept to include verification of the conclusions
discovered in the literature review by conducting a field study of experts. The integration of
data in concept analysis was unique to this particular method and offered au approach to
venfication of findings fiom the literature through collecting empirical data. The nature of
the concept was substantiated and the relevance of the concept to nursing was justified
through the use of actual clinical examples. Although this method suppoas the use of the
literature in uncovering the essential attributes of a concept, the fieldwork phase was not
feasible for achieving the goals of this analysis.
Rodgers. The approach to concept analysis developed by Rodgers (1993a) was based
on a philosophical perspective that acknowledges the changing nature of concepts. Rodgers
(1993a) provided a detailed perspective, identimg that concepts are not static and that they
are iduenced by contextual factors and evolution of the concept over tirne. The primary
purpose of this method was to provide a clear conceptual foundation as a guide for M e r
inquiry and, in doing so, to maintain a usefiil, applicable and effective concept. The eight
steps outlined were clear. The actuai method was very similar to the method describecl by
Wdker and Avant (1995). Like Waker and Avant (1995) however, it was unclear how the
apparent differences in philosophical underpinnings changed the way that this method was
applied. Roger's method (1993a) did include specinc reference to gathering data on
surrogate terms, related concepts and interdisciplinary and temporal comparisons, Rodgers
(1993a) also drew examples fiom the literature and h m expenence to fiirther illustrate the
nature of the concept. ûther steps in the method rernained the same as Walker & Avant
(1995). Rodgers (1993a) recommended sampling fkom the chosen population of literature,
The approach identifïed a manageable number of articles to be included in the analysis.
Classic or landmark articles could stilI be identined and included in the analysis. Rodger's
(1993a) purpose and rnethod of concept analysis were generaiiy congruent with the goals of
this study.
Siimmary of Research Design
The method selected for this concept analysis was a synthesis of three approaches
developed in nursing incIuding Rodgers (1993a), Schwartz-Barcott & Kim (1993) phase 1,
and Waker & Avant, (1995). These methods were selected due to the similarity of purpose
and feasibility of the method. A philosophical view acknowledging the changing nature of
concepts guided the development of the method. Significant factors influencing the
definition of the concept were considered in the method including contextual, societal and
temporal elements. Those elements of each method that were congruent with the
philosophical underpinnings and study purpose and objectives were included in the concept
analysis
The following research design has been adapted fiom Rodgers (1993a), Schwartz-
Barcott and Kim (1993) and Walker and Avant (1995). Although the steps are ordered, the
process is iterative in nature and includes the following:
1. Ident@ and describe the context in which the concept is discussed or studied-
2, Deterruine essential attributes. Idenm the combination of qualities or attriiutes
of this concept that make it different fiom other similar concepts. Definitions of the concept,
indicators used in mesures of SOI, and discussion and examples of the concept in the
literature provide usefid insight into the characteristics that set the concept apart fkom others.
The meanuig of the concept can be inferred fiom this data. Words, phrases, sentences and/or
descriptive passages of the data will be extracted from the text and analyzed.
3. Examine antecedents and consequences. Antecedents and consequences are
events or situations that precede or follow an example of the concept. These factors are
helpfûl in identifying whether the concept exists in a particular situation and are illustrated in
empincal examples of the concept.
4. Identie concepts or terms related to the concept of interest such as concepts
present in the literature that are used sirnilarly or together with SOI in the neonate. Surrogate
terms are alternative ways of expressing the concept using words not used by the student.
Related terms and concepts use different words and rneanings but the idea is somehow
related to the concept of interest and is used frequently in the same literature as the concept
of interest.
5. Describe al1 uses of the concept that can be discovered. Concepts can be used for
different purposes such as a predictor of a particular phenornenon or the end result of a
particular process. Usage reflects the nature of the concept and how health disciplines view
24
this concept in terms of its contribution to solving problems important to the discipline and
socieîy.
6. IdentiQ empirical examples of neonatal SOI indices or descriptions recorded in
the literature. Empirical instances of the concept found in the literature can help improve
identification of the essential attriiutes of SOI in the neonate and our ability to identify the
concept in practice.
7. IdentiQ implications for fiuther study fiom recommendations found in the
literature as well as insights gained fiom conducting the concept analysis. Implications for
M e r study and insights of the student will be set aside, recorded in a separate journal and
reviewed following the analysis. The results of this review will be included in the Ginal
discussion section of the analysis.
Selection of the Sample
Given the enomiity of the existing literature, it was not feasible to include all the
articles and books that pertained to SOI in the neonate, child and adult for this thesis. The
articles were limited to the neonatal population to support the purpose and objectives of this
study. As concems existed that sampling fiom the population of articles on SOI in the
neonate may have excluded important or influential sources, al1 articles meeting the sampling
criteria were included in the study.
The literature review was limited to articles published between January 1990 and
December 2000. Important advancements in neonatoiogy and economic pressures occurring
during this time f i m e significantly inauenced the development of SOI. Technological
advancements in the ventilatory care of premature neonates including widespread use of
surfactant and corticosteroids improved the outcomes of immature newboms. The cost of
neonatal care was being questioned more fiequentiy in the face of improved survival rates.
This penod of time was characterized by fiscal responsibility and the need for justification of
excessive resource use and spending. The need to address questions related to the
effectiveness of clinical care, resource use and the cost of care justified the proLifiration of
neonatal outcomes studies and the development of related neonatal measures. Investigators
recognized the potential relationship between outcomes and SOI. Leading measures of SOI
in the neonate were developed and implemented to attempt to adâress issues related to
different levels of SOI. This time k e best reflected curent use of the concept of SOI, as it
was applied to the neonatal population during the past decade.
Selection Criteria
Literature sources were selected for this analysis based on the following criteria:
1. The source focused on the neonatal population exclusively. A neonate was
defined as a newbom infaut pretexm to one month of age (Fetus and Newbom Cornmittee,
Canadian Paediatric Society, and Cornmittee on Fetus and Newbom, Committee on Drugs,
Section on Anaesthesiology and Section on Surgery, American Academy of Pediatrics,
2000).
2. Within the source, SOI was identified as a concept of interest. The concept had to
be discussed in sunicient depth to clarify and furiher develop understanding of the concept.
Sources had to discuss theoretical or conceptual development of SOI, conceptual or
operational definitions, observed dimensions of the concept, and/or SOI measures and
indicators. SOI had to be discussed as a general concept: not specific to a particular disease
or diagnosis.
3. Sources were cira- ftom the health disciplines literature: primarily articles
wrîtten by nurses and physicians. These professions have made a significant contribution to
the development of this concept.
4. Sources were identified fiom empirical literature published fiom January 1990 to
December 2000. Limitation of the sources to the last eleven years was supporteci by historic
and temporal infiuences on developments in neonatal care.
5. Sources were published in English. The inclusion of sources that required
translation was not feasible. A relatively low percentage of articles were published in
languages other than English (approximately 11%). Every effort was made to obtain articles
that had been translated.
Procedures
Cornputer Database Search. The identification and selection of sources was
conducted using primarily computer databases. Articles were selected for review ftom
Medline, Healthstar, Cinahl, Cancerlit and Embase databases. These databases were selected
because they are known to be primary sources of health literature for nurses and physicians.
Criteria for the search were developed based on the MeSH class~cation system used in the
Medline database and were applied uniformly across the five databases. The search criteria
were applied to each of the five databases in the following order: (a) a set of ail articles that
included neonates as subjects andor the 'heonate7' as a text word was identified, (b) a set of
al1 articles that included an index of severity of illness andior "severity of illness" as a text
word was identified, (c) the neonate set and the severity of illness set were combined to
create a set of articles that contained both neonates and severity of illness, (d) the combined
set was limited to articles published between 1990 and 2000 and was limited to the English
language. Appendix B shows the specific MeSH terms used to conduct the computer
database search.
In addition to the computer database search, a manual search of the reference iists of
the eligible articles was conducted. As the criteria for including articles in computer
databases has varied over time and the system for class@ing articles has differed among
databases, the completeness of a computerized literature search alone could not be
guaranteed. The manual search was added to improve the thoroughness of the search.
Abstract Scan. A screening procedure was applied to al1 sources meeting the
computer database search criteria. Abstracts of these sources were scanned for the followïng
criteria: (a) subjects had to be neonates exclusivety, no other age groups could be included in
the article, and (b) SOI had to appear in the text of the abstract or had to be iisted as a MeSH
subject heading. If an abstract was not provided in the computer database, the article was
automatically moved to the next level of review.
Reading of the Article. Each article that met the abstract scan criteria was read
completeiy. The articles were inciuded in the final sample as eligible articles if they met the
selection criteria for the study. A decision trail was recorded for any ambiguous sources (see
Appendix C). Articles that were excluded because they did not meet the selection criteria
were reviewed and reported in the results section. A separate reference list of ineligible
articles was kept (see Appendix E).
Review of the Reference Lists. Each reference list h m the eligi'ble articles was
reviewed to iden- additional articles. Each article identified was read completely. The
articles fiom the reference lists inciuded in the hal sample, had to meet the same selection
criteria as for Reading of the Article.
Data Collection
All data were extracted firom the sources and entered into a single chart includuig
description of the articles and data used to analyze the concept, SOI (see Appendix D). Data
were extracted in the form of words, phrases, sentences or entire paragraphs firom various
parts of each source. The type of data that was collected and recorded under each heading is
described in detail in the foilowing paragraphs:
1. Year of Publication (see Appendix D, column B). Each source of data was
identified by the year of publication.
2. Type of Publication (see Appendix D, column C). Each source of data was
identified by type of publication. The publication type was recorded as one of the following
types: (a) theoretical and/or conceptual (indicated by 'T3, (b) empirical research (indicated
by "R"), (c) systematic review of the literature (indicated by '2'3, (d) letter/commentary
(indicated by "C"), and (e) other (indicated by "O", accompanied by an explmation).
3. Author (see Appendix D, column D). AU of the authors of the source were
recorded by name.
4. Dennition of the Concept - Implicit or Explicit (see Appendix D, column E).
Whether the source provided an implicit or explicit definition of the concept of SOI of the
neonate was recorded in this column. The type of definition was indicated by an 'E' -
explicit or an '1' - implicit. Explicit definition- a plainly expressed and clear description of
an abstract idea that communicated the meaning of the concept that is usually presented to
the reader in the conceptuai h e w o r k section of an article, Implicit definition- a
description of an abstract idea that was not specifïcally expressed as a definition. Meaning
was implied or understood, communicated by the author through discussion of the concept
and/or the measures of the concept. Dimensions of the concept were used to imply the
meaning of the concept.
5. Definition of the Concept (see Appendix D, column F). Definitions of the concept
SOI in the neonate were identified and recorded as they appeared ongin- in each source.
Definition of a concept is an explicit description of an abstract idea communicating the
meaning of the concept.
6. Observed Dimensions (see Appendix D, column G). Dimensions or aspects of the
concept were ofien incorporateci into a definition of the concept and were recorded in this
section. A definition of the concept, however, did not always exist in every source.
Discussions of various aspects or dimensions of the concept occurring in ai l parts of a source
were examined and recorded. Identification of observed dimensions such as physiological
and behavioural aspects of a concept provided implicit information about the concept. This
type of descriptive discussion linked the conceptual to the operational definition and
contributed to identification of the defining characteristics,
7. Operational Definition (see Appendix D, column H). The operational definition
translated the concept into measwable terms by describing the procedures that indicated
whether, and to what degree the variable was present. A clear explicit operational definition
existed in some sources (e-g., a dennition that described the measurable physiological and
behavioural components of SOI). Alternatively, the indicators were listed. Specific
indicators were identifid and used to reflect the concept. These indicators were ofien
discussed as domains of the concept in the text of the source, such as in the discussion or
results section of an empirïcal study.
8. Name of the Measure and /or Indicators (see Appendix D, column 1).
The name of the scale or measure of SOI was extracted h m the source. Whenever possible,
examples of the indicators used in the scale were iisted- In some cases, the content of the
measure was reflected by discussion, description or use of the indicator. For example, the
procedures and operations used to measure the concept were described as ïndicators such as
blood pressure.
9. Concept Usage (see Appendix D, column J). Use of the concept was identifid
(e-g., part of an initial assessment, part of a theory, an independent or dependent variable, a
descriptor of a population, or a control variable). Extracted data included under what
conditions and for what purpose the concept was used. Concept usage also reflected the
importance of this concept to health disciplines.
10. Description of Context (see Appendix D, column K). Monnation regarding
who, where and under what cucumstances the concept was discussed, was extracted.
Specifically, profession of the author (Registered Nurse (RN), Physician (MD),
Multiprofessional, both @2N and MD) or other), setting (acute, chronic, acute and chronic, or
community), and patient characteristics (fûll terni, preterm, both, other) were recorded.
1 1. Surrogate Tems (see Appendix D, column L). Tems that are used to refer to
SOI were recorded. Terms having similar rneanings to SOI were identified by
interchangeable or overlapping usage, implicit or explicit discussion of related rneanings,
andor shared definhg characteristics. Words, sentences or paragraphs that served as
evidence of similar meaning or relatedness will also be recorded.
12. Empirical Examples (see Appendix D, column M)- Empincal examples of the
concept were extracted from the sources.
Data Management
Each source was numbered and read in its entirety. Data fiom each source were
numbered and entered on the data collection chart (see Appendix E). Pertinent data were
used for two difEerent purposes, description of the sample and analysis of the concept.
Descriptive data were extracted and entered on the data collection chart, columns B, C, D, E,
F, 1, J, K and L. Data used for the analysis of the concept were extracted fiom each source
and entered on the data collection chart, columns F, G, H, 1, J and M.
Descriptive data were analyzed and displayed in tables and figures. Data reflecthg
the essential attributes of SOI were grouped into categones. Each category was labeled and
represented one essential attriibute. Other data representing antecedents, consequences, and
related factors were grouped and labeled as categories. Uses of SOI were described and
summarized. Surrogate terms were displayed in table format. Empirical examples were
identified and discussed in the hdings. A reference Iist of al1 sources selected for the
analysis was included in the reference section and marked with an asterisk. A reference list
of al1 excluded sources was developed (see Appendix E).
Records
Record books were kept as an audit traii to document ideas, issues, insights and
questions that arose during the study. Four separate books were kept to record information
related to the study (see Appendix D). This infornation was reviewed foiiowing completion
of the analysis and issues were addressed in the discussion section of the thesis-
Rigor
The rigor of the data analysis was supported in three ways: (a) the descriptive data
were presented in tables and graphs, (b) the process of categorizing data was checked using
two verification tests, and (c) an audit trail of decision making and idea development was
maintained.
Two verifkation tests were conducted to check the rigor of the process of
categorizing data. The student @CS) reviewed the first 10 articles that met the selection
criteria of the study. Data were extracted from the articles and entered on the data collection
chart (see Appendix D). The student analyzed the data by sorting it into categories of
essential attributes according to the data analysis procedures that follow this section. The
student labeled each category of essential attributes. These data then were distnbuted to two
clinical experts in neonatai care. Both clinical experts were clinical nurse specialist/nurse
practitioners who were actively employed in neonatal intensive care units at two large
teaching hospitals. The first clinid expert was given a sample of extracted data (8 1 pieces
of data fkom 10 articles) to sort into the categories labeled by the student. The practitioner
was provided with a set of category labels. The practitioner was asked to sort each piece of
data according to the following Wntten instructions: (a) Enclosed, please find 81 sentences,
phrases or words that each represents a piece of data; (b) The data have been provided in
random order on the subsequent four pages; (c) 1 have provided you with 10 categones of
atûibutes that characterize the concept of SOI in the neonate; and (d) 1 would like you to
organize the data under the categones provided.
The second clinical expert was given extracted data that had been grouped into
categories by the student. This practitioner was not provided with the category labels but
was asked to generate labels for each group accordhg to the foilowing instructions: (a) Each
page contains data that has been grouped together to represent an essential attribute of SOI in
the neonate; and (b) Please develop a title for each page that best reflects the essentiai
attribute represented by the category.
An audit trail was kept to monitor decision-making and the development of ideas
during the study. The record book focused on the following four areas: (a)
inclusion/exclusion of data, (b) methodological decisions, (c) data analysis procedures, and
(d) self-awareness of the researcher. The rationale for making decisions was included in the
record. The record was used to monitor and track aspects of the evolvhg data analysis and
supported the dependability and credibiiity of the concept analysis (Rodgers & Cowls, 1993).
Data Andysis Procedues
Selection of the Sample
A senes of selection criteria were applied to realize the £inal sample of articles
including a compter database search, abstract scan, complete reading of the article and
reference list review. A schema was used to display the sarnpling process and number of
articles included/excluded.
Description of the Sample
Data fkom the eligible articles (see Appendix D, columns B, C, E, 1, K, J, L) were
analyzed using descriptive statistics. The number of setting types was reported in the
hdings. Relative fkequency distribution tables were used to communicate findings related
to the author type, patient type, and publication type. Frequency distribution graphs were
used to display the following descriptive information: the year of publication of the articles,
and the neonatal rneasures of SOI identified in the articles. Surrogate tems used in place of
SOI were reported in table format. Conceptual definitions of SOI were identifiecl in the
eligible articles and reported in the hdings.
Analysis of the Concept
Articles in the sample were read for content related to the concept SOI. Content
pertaining to a conceptual model, definition of the concept, description of qualities or
dimensions of the concept, operational definition, how the concept was measured, what
indicators were used and uses of the concept were identified (see Appendix D, columns F, G,
H, 1, and J). Words, phrases, sentences and paragraphs related to SOI were extracted. Data
were grouped together based on similar themes. Each groupingkategory represented a
potential attribute of the concept. The categones were Iabeled. Some units of data could fit
into more than one category if more than one theme existed within the phrase or paragraph.
To identiQ the cntical ideaitheme used to categorize the data, the key word or phrase was
underlined. Individual units of data were compared to each other within each category to
ensure consistency of data within categones. Inconsistent data were reorganized into new
categories, related categories or removed altogether. Category labels were adjusted to fit the
data. Relationships between the categones and the concept SOI were examined to determine
attributes, antecedents and consequences. A definition of the concept and a conceptual
model were generated, based on the categories identified. Essential attributes of the concept,
antecedents, consequences, and related factors were incorporated into the dennition of the
concept and the conceptual model. The next section provides the results from this analysis.
CHAPTER THREE
Results
The purpose of this study was to idente the essential attributes of SOI in the neonate
and to develop a definition of the concept from the literature. A sampling process was
applied using a series of inclusion criteria to derive the final sample. Description of the
sample of articles includïng the type of author, patient, setting, and publication, year of
publication, measures of SOI used, sunogate temis, and definitions of the concept was
undertaken to identifjr the context of the concept. Analysis of the content of the selected
literature identified categones of data related to SOI as attributes, antecedents, consequences
and related factors. Also, other fïndings including uses of SOI and empincal examples were
discussed. Findings of the analysis were incorporated into a definition of the concept and a
conceptual model. The focus of this section was to describe the context of the study using
descriptive data and to present the kdings fiom the concept analysis.
Verification Tests
Two verification tests were conducted to check the rigor of the process of
categorizing data. Each verification test exarnined a different aspect of the process of
categorizing data. Data collected from the h t 10 sources (14% of the sample) were
distributed to two dinical experts in neonatology.
The first clinical expert was provided with the data and the labels (derived by the
student) for 10 categories and was asked to sort the data into categories representing essential
attributes of the concept. Fifty-three of 81 pieces of data were sorted in agreement with the
student resulting in a 65% rate of agreement between the first clinical expert and the student.
Subsequently, the student discussed the sorting of data with the first clinical expert and the
rate of agreement improved. The exact percentage of agreement was not recalculated, as the
student did not keep a record of each piece of data that was categorized differentiy following
this discussion,
The second clinical expert was asked to independently generate namedlabels for the
categories of data. Of the 10 categories of data, 5 of the labels matched those derived by the
student. The student chose to meet with the practitioner to discuss the remaining five
categories and to work towards achieving a consensus. Subsequently, four of the titles were
revised and a consensus was achieved in 9 of 10 category labels. Therefore, 90% agreement
was achieved.
By comparing the work of the student with clinical experts in neonatology, the ngor
of categorizing data was maintained. Although the first test, sorting the data into categories,
showed a moderate level of agreement (65%), consensus improved after the student
discussed the results of the sorting with the clhician. The student was unable to report this
improvement, as the level of agreement was not recalculated. In the second test, 90%
agreement was ultimately achieved. The student was not able to compare the percentage of
agreement between the two verifkation tests because they were independent and different
exercises. The percentage of agreement between the student and the ciinical experts indicated
that the clinicians generally supported the accuracy with which the student conducted this
part of the analysis.
. Selection of the Sample
In Figure 1, a schema shows the selection process for the study sample. There were
two sources of eligible articles in this study, the computer database search and the review of
the reference lists fiom eligible articles fkom the computer search.
Computer Database Search (n=l768)
Abstract Scan Did Not Meet
Selection Criteria Selection Criteria (n=1616)
Reading of Article Reading of Article Not Eligible Eligible
Review of References Lists Yielded Additional
Articles Eiigible (n=13)
Total Articles Eligible (n=71)
Figure 1. Schema of sample selection. The study period was fiom l W O / O 1/0 1 to
2000/12/3 1.
Using the computer search criteria (describecl earlier), articles were identified for
fiuther review fiom the foIlowing five computer databases: Medline, Cinahl, Cancerlit,
Healthstar, and Embase. Eleven percent of the articles identified in the computer database
search were non-English and thus did not meet the search criteria (n=2 1 8). Abstracts of the
articles meeting the search criteria were scanned. Articles meeting the abstract scan cnteria
were then read completely. Of the 152 articles that were read completely, 94 did not meet
the inclusion criteria for the following reasons: (a) they did not meet age criteria, (b) the
terrn "severity of illness" was not used explicitly in the article, (c) the measurement of SOI
was isolated to a specinc disease, and (d) the article did not include enough discussion of the
concept. In the articles that did not meet age cnteria (n=22), neonatal content could not be
differentiated &om pediatric content as the articles included broad age groups. Other articles
did not use SOI explicitly (n=25). For example, other terms such as mortality nsk, were used
in place of SOI and were measured using SOI measures or SOI was used in the abstract, but
was not used in the article. Articles containing disease-specific measures of SOI were
excluded (n=29). These measures were narrow in scope and purpose and did not apply
broadly to al1 neonates. Lastly, articles were excluded because they contained insuficient
data (n=18). None of the sentences, phrases or words contributed to understanding of the
meaning of SOI and therefore, no data could be collected and categorized fiom these articles.
Description of the Sample
Author, Patient and Settinp: Types
Contextual data included author type, patient type and setting type. Most articles
were published b y physicians (MDs), while a smaller number were pub iished by nurses
(RNs) (see Table 1). Multiprofessional authors were groups that included at least two
different health care disciplines. When RNs authored articles with MDs, however, the term
used was both RNs and MDs.
The settings for all articles were mute care settings, primarily neonatal intensive care
units. Al1 articles discussed SOI in the neonate including pretemi and U t e n n neonates
admitted to intensive care units (see Table 2). The type of neonates most co~nmonly written
about was equally divided between preterm only and both preterm and fÙliterm infmts.
Table 1
Relative Frequency Distribution of Author Types in Sample of Articles
Author Type f 'Y0
MD
RN
Multiprofessional
Other
Both RN & MD
Table 2
Relative Frequency Distributions of Patient Types in Sarnple of Articles
Patient Type f %
Both Preterm & Tenn 34 48
Preterm only 34 48
Fulltem only 2 3
Publications: Type and Year
Of the 71 publications, the majority were research reports (see Table 3). Other types
of publications included letters, literature reviews, discussion papers, annotations, and
database development. The number of articles written about SOI in the neonate has steadily
increased over the eleven-year study period, with the exception of a slight drop in the number
of articles in the year 2000, as shown in Figure 2.
Table 3
Relative Frequency Distributions of Publication Type in Sample of Articles
Publication Type f %
Research 59 83
Literature Review
Discussion Paper
Annotation 1 1 -4
Database Development
1990 1991 1992 1993 1- 1995 1996 1997 1998 1999 2000
Year of Publication
F i w e 2. Frequency distribution by the year of publication in the sample of articles.
Memures
Frequency distribution of the use of neonatal SOI measures is displayed in Figure 3.
A total of 21 different measures of SOI in the neonate were used in the sample of 71 articles.
Each neonatal measure and its indicators are listed in Appendix F. Of the 21 measures
identified, 8 neonatal measures dominated the Literature including the S N A P group (4
measures) (Richardson, Gray, McCormiclc, et al., 1993), CRIB (Tamow-Mordi et al., 1 WO),
NTISS (Gray, Richardson, McCorrnick, Workman-Daniels, et al., 1992)- TISS (Cullen et al.,
1974) and PSI (Yeh et al., 1984). Together, these eight measures were used predomïnately
(72%) in the sample of articles.
SNAP is an acronym for a neonatal SOI measure titled Score for Neonatal Acute
Physiology (Richardson, Gray, McConnick, et al., 1993). The term SNAP group refers to a
family of measures derived fiom and including the original SNAP (Richardson, Gray,
McCormick, et al., 1993) including the Score for Neonatal Acute Physiology Perinatal
Extension (SNAP PE) (Richardson, Phibbs, et al, 1993), Score for Neonatal Acute
Physiology Vital Signs (SNAP-VS) (Roblin et al., 2000), and Score for Neonatal Acute
Physiology II (SNAP II) (Cheung & Robertson, 2000). The original SNAP was used
predominately (24%) in the articles on SOI in the neonate, foilowed by SNAP PE (IO%),
SNAP VS (1 %), and SNAP II (1 %). These percentages express the total use of the
individual S N M measures among al1 of the sample articles.
+O y Severity of iliness Measures
F i m e 3. Frequency distribution of the use of neonatal SOI measures. Measures are used
100 times in 71 articles. SNAP group is composed of the following measures: SNAP =
Score for Neonatal Acute Physiology, SNAP PE = SNAP Perinatal Extension, SNAP VS =
SNAP Vital Signs, and SNAP II = SNAP Version II. Other additional measures consist of
CRIB = Clinical Risk Index for Babies; NTISS = Neonatal Therapeutic Intervention Scoring
System; TISS = Therapeutic Intervention Scoring System; PSI = Physiologie Stability Index;
NMS = Neonatal Morbidity Scale; PM DRG = Pediatric Modified Diagnosis Related
Groups; DRG = Diagnosis Related Groups; PRISM = Pediatric Risk of Mortality Score;
APGAR = Appearance, Pulse, Grimace, Activity, Respiration; and NBRS = Neurobiologie
Risk Score. 'No Formai Measure" included articles using individual indicators to measure
SOI. "Other" included formal measures having multiple indicators that were used
infiequently in the articles. For a complete List of measure names, acronyms, and indicators
see Appendk F.
Surrogate Terms
A total of 53 different terms were used to indicate SOI. Surrogate tenns for SOI used
in the articles, are iisted in Table 4 by groups defhed by the investigator. Many terms, such
as severity of underlying illness, severity of acute illness, and illness severity linked severity
and illness in dif3erent ways. A h , the word sick or sickness was associated with many
surrogate terms used for SOI. The word, disease, was ffequentiy used in place of illness.
Risk was fkequently used in place of SOI. Overail, a variation terrns in the use of surrogate
tenns was identified fiom the articles.
Table 4
Surrogate Tenns for Severity of Iüness in the Neonate
Grouping Ternis
Severity of nlness severity of illness, iliness seventy, severity of neonatal iliness, severity of underlying iliness, severely ill, severity assessment, severely ill infant, severity of acute ihess, severity, infant severity of illness, severity of infant illness, extremely severe iliness, severity scores, admission severity, severity of presentation, severity level of the disorder
Sick
Risk
how sick, sick infmts, sicker infants, extremely sick, very sick infants, sick preterm iafant, sick neonate, ill infant, iU preterm infant
clinical risk, mortality risk, high medical risk, initial neonatal risk, risk, high-risk preterm, illness risk, risk scores, risk scoring system, health risk
Disease disease severity, severity of disease, seventy of underlying disease
Condition condition of the newbom, actual severity of the premature infmt's medical condition, neonatal condition, immediate condition of premature newbom
Critical cntically ill, critical illness
ïllness underlying degree of ilhess, degree of illness
Physiological physiologically unstable, physiologie stability
Health health status
Definitions of the Concept
Two of the 71 articles used an explicit definition of the concept. These definitions of
the concept were extracted fiom the introductory paragraphs of the articles and were not part
of the conceptual fkamework of the studies. The definition developed by Stevens and
Johnston (1 994) used stability as its central idea and supported the conclusion that stability is
an essential attribute of SOI. "Severity of iliness was dehed in terms of the infant's
physiologie stability." (Stevens & Johnston, 1994, p. 227). Almeida and Persson (1998)
identified suffering and disability as the primary attributes of SOI. "Seventy of illness is
concerned with s u f f e ~ g and disability, which are the properties of the individual." (Almeida
& Persson, 1998, p.12).
Analysis of the Concept
Definition of Severity of Illness in the Neonate
SOI is characterized primarily by instability of the neonate that manifests itself as
changes in the physiological domain. Other attributes identified including s u E e ~ g and
disability, had less support in the literature. Antecedents to SOI, maturational and
developmental factors, include characteristics of the neonate such as birth weight, gestational
age and congenital anomalies. Therapeutic intervention occurs as a consequence or response
to instability. Stress, capacity for behaviour and complication in the neonate are associated
with SOI as related factors. A conceptual mode1 was developed to illustrate these
relationships (See Figure 4).
1 RELATED 1 1 RELATED 1 1 RELATED
ANTECEDENT CONSEQUENCE
NEONATAL CHARACTERISTICS
ILLNESS Intervention Maturation DeveIo~ment
FACTOR
COMPLICATION
ATTRIBUTE
iNSTABLL1TY
Derangements L A
FACTOR
CAPACITY FOR BEHAVIOUR
F i m e 4. Conceptual Model of Severity of Illness.
FACTOR
STRESS
Attributes
Instability. The label instability was chosen to reflect the primary essential attribute
or characteristic of SOI. The t e m . instability and stability were used consistently
throughout the data, examined as two ends of a continuum; Stability as it reflects SOI,
implies consistency in contrast to instability that implies potential for change or alteration to
homeostasis within an organism. 'The assumption of derangements of homeostasis leading
to a hal common pathway toward death or damage is generdly reasonable." (Richardson,
Tarnow-Mordi, & Lee, 1999, p. 263). Although both tems were used in the literature,
instability \vas selected to represent this attribute. As the primary context for SOI in the
neonate was the neonatal intensive care unit, instability best reflected the condition of a
neonate likely to require this level of monitoring and support,
In the data, instability and stability were consistently and clearly linked with SOI in
the neonate (Davies, 1995; Johnston & Stevens, 1996; Petryshen, Stevens, Hawkins, &
Stewart, 1997; Richardson, Shah, et al., 1999; Stevens & Johnston, 1994). The following
examples demonstrate the use of this attribute as reflecting SOI:
1. ". . . b y quantiS.ing physiologic stability, the PSI provided an overail assessrnent of
the infant's severity of illness."(Petryshen et al., 1997, p. 240).
2. "Severity of illness was defineci in terms of the infant's physiologic stability."
(Stevens & Johnston, 1994, p. 227).
3. "SNAP from the second 12 hours primarily indicates the effectiveness of early
medical interventions and, to a certain extent, physiologic stability (or instability)." (Petridou
et al., 1998, p. 1042).
4. "In contrast to APACHE & PSI, a patient may receive points for both high and
low values of a single physiologic measure because this represents more extreme physiologic
instability-" (Richardson, Gray, McConnick, et al., 1993, p. 617)
5. "The seven systems measured (PSI) are: cardiovascular, respiratory, central
nervous system, haematologic, renal, gastrointestinal, and metabolic. The higher the score,
the more severe the physiologic instability." (Davies, 1995, p. 307)
6. T h e fiequency of bacteremia was exarnined, since blood cultures are performed
when neonates display nonspecific signs of clinical instability such as apnea, bradycardia,
temperature instability or feeding intolerance. Aithough bacteremia workups have never
been tested formally as an index of severity of underlying illness, it is reasonable to assume
that physicians are more likely to obtain blood cultures f?om neonates who appear more
critically iU." (Freeman et al., 1990, p. 328)
7. ". . .the greater the severity of illness and the degree of instability of vital
physiologic variables on admission to an NIW, the more likely that infant is to die."
(Phamah, 1998, p. 1070)
8. "Advancing gestation had a powerfiil impact on neonatal stability, with a drop of
more than one SNAP point for each additional week of gestation." (Richardson, Shah, et al,
1999, p. 515)
Physiologie indicators were used to measure SOI. These physiologic indicators of
instability reflected derangements in organ system functioning, for example; "A score, the
PSI, has been developed that quantitates physiologic stability and therefore directly assesses
SOI.. .The PSI score assesses a total of 34 variables fiom seven physiologic systems.. .Where
modified for neonatal physiologic variables, the limits assigneci depend on age." (Davies,
1995, p. 307).
The derangements were m d e s t e d as abnormal values on tests such as laboratory
tests, vital signs and physiologic assessments. The data supported this conclusion as 19 of 21
neonatal SOI measures identifïed in the sample used physiological indicators in theu
measures (see Appendix G). Derangements of physiological and laboratory parameters were
used as the primary indicators of SOI and reflect changes in physiologic functioning-
Other Attributes
Sufferinn and Disability. Suffiring and disability were identified as attributes of SOI
in only one of the selected articles. Almeida and Persson (1998) offered a very different
perspective than the other authors, suggesting that srnering and disability were the primary
attributes of SOI, "Severity of illness is concerned with suffering and disability, which are
the properties of the individual." (Almeida & Persson, 1998, p. 12). They argued that CRIB
and SNAP were developed to predict risk and measured a different but related concept,
severity of disease. The characteristics, suffering and disability of the individual, were not
discussed in depth by Almeida and Persson (1998) and were not identîfïed and supported by
data fiom other selected articles.
Antecedents
Maturation and Development. Gestational age, birth weight, and congenitai
anomalies are indicators of maturation and development in neonates (Davies, 1995; McKim,
1993). As such, they represent characteristics of the individual neonate. The selected data
indicate that maturation and development factors have been clearly linked to SOI.
Gestational age and birth weight have been used as proxy indicators of SOI (Almeida
& Persson, 1998; Richardson, Gray, McConnick, et al., 1993; Richardson & Tarnow-Mordi,
1994; Wang, Chemg & Chen, 1994). One leading measure of SOI, CRIB, incorporates birth
weight, gestational age and congenital anomalies as indicaton (INN, 1993). These indicators
are identified as additional risk factors added to the physiology-based measure to predict nsk
of mortstlity and contribute little to the measurement of SOI (Richardson, Tarnow-Mordi, et
al., 1999). Another measure, SNAP PE, also uses, ". . .birth weight, apgar score and smali
size for gestational age as additional independent predicton of outcornes." (Hanna et al.,
1997), extending the SOI score (SNAP) to predict risk (Stevens et al., 1999). Congenital
anomalies have also been identified as indicators of SOI that are used as separate risk factors
in measures of SOI (Richardson, Tamow-Mordi, et al., 1999; Davies, 1995). The selected
literature indicates that as a characteristic of the neonate, maturation/development is related
to SOI as an antecedent. The following excerpts illustrate the nature of the relationship:
1. '2ower gestational age was associated with greater severity of ihess. * ."
(Richardson, Shah, et al., 1999, p. 515).
2. "Advancing gestation had a powerfùl impact on neonatd stabiiity with a drop of
more than one SNAP point for each additional week of gestation." (Richardson, Shah, et al.,
1999, p. 515).
3. "Factors such as assisted ventilation, oxygen needs and severity of iliness differed
between the age-groups. These differences were by virtue of group membership based on
degree of imrnaturity.. ." (Johnston et al., 1996, p. 439).
4. C'Measures of severity of illness for the period up to 48 hours of age reflected the
eEects of interaction among maturity, severity of ihess and therapy-" (Perlman et al., 1995,
p. 85).
5. ". . . o h ilI, immaturely developed infant." (McKim, 1993, p- 89).
6. ". . .the length of hospitalization was a.€fécted by the degree of premanirity and the
severity of the medical complications (the lower the birth weight the longer the stay in
hospital.. .)" (McKim, 1993, p. 92).
7. "The assumption of derangements of homeostasis leading to a final common
pathway toward death or damage is generally reasonable. However, for certain classes of
patients, these assumptions may break down. The most obvious are congenital anomalies
where standard physiology no longer obtains. An infant with a cyanotic congenital heart
disease may show oniy a single abnormal value.. .yet may have a life-threatening illness."
(Richardson, Tarnow-Mordi, et al., 1999, p. 263).
8. "Presence of a life-threatening congenital anomaly had the largest impact, adding
4.0 points [of 4 potential points to the SNAP score]." (Richardson, Shah, et al., 1999, p.
514).
9. "In the era when general neonatal surgery was making its greatest strides, illness
severity [SOr] in patients with correctable but lethal congenital anomalies was determined by
three factors, birth weight - used to represent gestational age or physiological maturity -
associated clinically significant congenital abnomalities, and infection." (Davies, 1995, p.
3 06).
10. ". . . we cannot comment on whether diagnosis of major congenital anomalies
such as lower bowel obstruction and heart defects initiated at home rather than at birth
hospitals was associated with diBirences in severity of illness on teadmission. - -" (Lee et al.,
1995, p. 763).
Maturation and development indicators reflected unique preexisting characteristics of
the neonate, which have been shown to influence SOI in the neonate as a determinant or
antecedent. These indicators may influence the degree of instability but may not directly
reflect SOI.
Consequences
Therapeutic Intervention, Therapeutic intervention was discussed in great depth in
the selected data. Many measures of SOI including the Neonatal Therapeutic Intervention
Scoring System (NTXSS) (Gray, Richardson, McConnick, Workman-Daniels, et al., 1992),
S i n . Score (Fleisher et aI., 1997) and others, as weU as informal measures, were composed
of therapeutic indicators. The most common indicators included ventilatory assistance and
length of stay. A relationship clearly exists between SOI and therapeutic intervention. 'The
likelihood of admission into NICU and the duration of both MCU care and hospital stay are
proportional to the degree of illness."(Roblin et al., 2000, p. 1535).
Therapeutic intervention has been described by authors as a proxy rneaswe (Freeman
et al., 1990; Lee et al., 1995) and as an indirect measure of SOI (Gray, Richardson,
McCormick & Goldmann, 1995; Hazebroek, et al., 199 1 ; Stevens, Richardson, Gray,
Goldmann & McConnick, 1994). As therapeutic intervention did not reflect SOI in a direct
way, it was concluded that it is not an attribute of SOI.
Therapeutic intervention has been described as a response to instability of the neonate
(e-g., ". . .medical treatments occur after an ihess has been present for some time.. ."
[Holditch-Davis & Lee, 1993, p. 2551 and ". . .require extensive therapeutic support to
achieve their physiological stability. ." [Stevens, Richardson, et al., 1994, p. 9481). These
examples indicate that therapeutic intervention logically follows SOI. Other data extracteci
fiom the selected articles described therapy as providing assistance (Roblin et al., 2000;
Richardson & Tarnow-Mordi, 1994) and support to the neonate (Avila-Figueroa et al., 1998;
Catlett, Miles & Holditch-Davis, 1994; Miall et al., 1999). Based on the evidence in the
selected data, this author concluded that therapeutîc intervention occurs as a consequence of
SOI.
Related Factors
Complication. Data fiom the selected literature indicated that a relationship exists
between SOI and complication, however the nature of the relationship was unclea- Very
few articles discussed the association between SOI and complication. DiEerent ideas about
the nature of the relationship were expressed but few explained the ideas in suficient depth
to cIari@ whether complication was related to SOI as aa attribute or a related factor.
Complication was used as an indicator of SOI using diverse approaches: (a) fkequency of
complications (Helfkich Jones & Smyth, 1999), @) single complication used as a proxy
measure (Lee et al., 1995), and (c) twenty of the most common diseases and
pathophysiological states were rated for SOI (Catlett et al., 1994; Holditch-Davis, 1990). In
another article by Stevens et al.(1996), complication was identified as an indicator of
functional status (functional status was identified as a related factor to SOI). The data
provided support for the existence of a relationship between complication and SOI. Excerpts
fiom the selected data that identiQ the relationship include:
1. "They had signincantly more medical complications, lower birth weights, and
younger gestational ages at birth. They spent more days on mechanicd ventilation and had
higher overaU illness severity."(Holditch-Davis & Lee, 1993, p- 259)-
2. "Severity of illness as a consequence of NICU is ofien directly related to the
functional status of preterm infants as measured by physiological stability and the potential
for CO-morbidity and/or complications." (Petryshen & Stevens, 1995, p. 1046).
3. "As proxies for severity of illness, the number of deaths and the length of stay
after readmission were measured." (Lee et al., 1995, p. 760).
4. "Significant differences in Neonatd Medical Index risk categories resulted nom
neonatal complications during hospitalization and may be related to the effects of therapy."
(Anand et al., 1999, p. 339).
An association between complication and SOI was identined but the nature of the
relationship was not clear. Diverse approaches to the measurement of SOI were used but
were not well explained. Therefore, complication was considered a related factor that can
influence and be influenced by SOI.
Capacity for Behaviour. Capacity for behaviour was identifïed as a related factor. A
small amount of evidence was available to identify this relationship including some of the
following excerpts ffom the data:
1. ". . .support for a profile of infmt behavioural responses to a tissue-damaging
stimulus that c m be modulated by factors such as behavioural state and severity of
illness."(S tevens, Johnston & H o m 1994, p. 108).
2. ". . .overd severity of iilness had only minor effects on the development of
sleeping and waking in the preterm period."(Holditch-Davis, 1990, p. 523).
3. "Severity of illness affects the cry response to pain, not facial action or
pathophysiological arousal in response to pain-"(Johnston et al., 1999, p. 588).
4. ". - .cry characteristics are thought to reflet the infant's biologicd integrity or an
index of underlying stress.. .due to neurological disorganization, sicker infants produce cries
that are higher pitched, tense, grating, and generally more demanding than healthy infants."
(Stevens, Johnston, et al., 1994, p. 107).
5. b'However, there was a sienificant interaction between severity of illness and
behaviowal state. It could be hypothesized that the physiological responses [to pais of those
infants who were in quiet sleep and most severely iIl would be most affkcted." (Stevens &
Johnston, 1994, p. 230).
Behaviour was used as an indicator of SOI in the Apgar score, however the Apgar
score was used only once on its own to measure SOI (Apgar, 1953). The Apgar was
incorporated as an indicator into several other mesures including SNAP PE, SNAP II and
NICHD and was used more fiequently; the rationale for its inclusion was unclear (Apgar,
1953; Cheung & Robertson, 2000; Richardson, Phibbs, et al., 1993; Poilock et al., 2000).
Capacity for behaviour was discussed in a limited way in the fiterature, as being a response to
SOI or as having a relationship with SOI. Based on the selected literature, capacity for
behaviour was not considered an attribute or a consequence of SOI, but a related factor.
Stress. Ideas about stress were identified fkom a very small amount of data- In one
excerpt, degree of stress was evaluated using physiologic stability and measured using
SNAP, "The Score for Neonatal Acute Physiology (SNAP) c m be used to assess the level of
physiological stress in critically il1 infants." (Petryshen & Stevens, 1995, p. 1047). In the
second excerpt, Stevens, Johnston, et al. (1994) connecteci stress to neurological
disorganization, as indicated by cry characteristics, ". . .cry characteristics are thought to
reflect the infant's biological integrïty or an index of underlying stress.. .due to neurological
disorganization, sicker infânts produce cries that are bigber pitched, tense. grating, and
generally more demanding than healthy infants."@. 107). Stress and SOI are linked as a
measure of SOI, SNAP, is used also to measure stress. Stress is a related factor-
Uses
The significance or relevant purpose of the concept is reflected in its use (Rodgers,
1993a). The use of the concept influences the development of that concept. The use of the
concept is a means of expressing the relevant attn'butes. SOI has been used in a variety of
capacities in research. Authors have discussed 0th- potential applications in letters,
commentaries and reviews of the fiterature. The following paragraphs descnbe many uses
for SOI.
Articles described potential uses in addition to actual uses. In an article that
described developing a patient classification system, SOI was incorporated into the measure
(Almeida & Persson, 1998). The measure was used primarily for assessing outcornes but
also identified many potential uses for the measure including making decisions on stafnng
requirements, critena for referring mothers and newboms, identiwg staff education and
training needs, standard cnteria for patient information and prognostic systems for medical
decision support (Almeida & Persson, 1998). Other articles surnmarized trends in the use of
SOI including comparative studies of outcome between hospitals or individual clinicians,
payment systems and the use of SOI as a basis to forgo treatment (Perlman, 1998;
Richardson & Tarnow-Mordi, 1994).
In research, study groups were ofkn stratifiai on SOI, such as in investigations of the
incidence of interhospital transfers among insured and uninsurd patients @urbin, Giardino,
Shaw, Harris, & Silber, 1997) and of the number of tests orderd by house staEphysicians
(Griffith, Wilson, Desai, & Rich, 1997; 1999). Many articles used or discussed SOI as a
clinical outcome of care (Johnston et al., 1999; Lee et al., 1995; Petryshen & Stevens, 1995;
Schibler, et al., 1998; Stevens et al., 1996; Wang et al., 1994). In one study, readmission
rates and SOI were examined in nemates having been discharged home early fiom hospital
(Lee et al., 1995). Frequently, SOI was used as a demographic variable that was compared
between two grouped of patients being studied (Anand et al., 1999; Freeman et al., 1990;
Johnston & Stevens, 1996; Holditch-Davis & Lee, 1993; Petryshen et al., 1997). In one
study, three groups of infants receiving two different types of analgesia and a placebo were
compared for SOI (Anand et al., 1999).
In other studies, SOI was considered a risk factor for mortality and was combined
with other factors such as birth weight and gestational age to predict mortaiity (Fleisher et al.,
1997; INN, 1 993; Richardson et al., 1998; Richardson, Pbibbs, et al., 1993; Richardson,
Shah, et al., 1999; Scottish Neonatal Consultants' Group, 1995; Stevens, Richardson, et al.,
1994). Two studies compared several measures of SOI for their ability to predict morbidity
and mortality (Fleisher et al., 1997; Pollack et al., 2000). SOI was also studied as a risk
factor for other chical outcornes such as bacteremia (Beck-Sague et al., 1994; Gray et al.,
1995). In other research studies, SOI was used as a variable in a correlational study such as
parental sensitivity and SOI and also in a correIational matrix to determine relationships
between multiple technology use, SOI, and other factors (Almeida, Panerai, de Carvalho, &
Lopes, 2 99 1 ; Catlett et al., 1 994; Hanna et al., 1997; Kratochvii, Robertson, & Kyle, 199 1 ;
McKirn, 1993; M i d et al., 1999; Shi et al., 1993; Swietlinski, Bujniewicz, & Musialïk, 1992;
Zahr & Cole, 1991) Another study examined the relationships between elevations of nitrite
plus nitrate and SOI (Shi et al., 1993). SOI and birth weight were used as objective measures
against which RN and MD estimates of mortality nsk were measured (Stevens, Richardson,
et al., 1994).
Reviewulg the uses of the concept in the selected articles has identified the possible
range of its uses. The successfid application of SOI in research and practice implies that it is
relevant to understanding the care requirements of neonates.
Empirical Examples
Three excerpts of SOI were extracted fkom the selected articles in whole sentences.
Selection of an empirical example was based on its ability to reflect attributes, antecedents
and consequences of SOL and to i d e n w relationships drawn fiom the data about the general
nature of the concept.
1. "In a number of children, postoperative complication or unsalvageable cardiac or
renal anomalies leading to rend insufnciency were considered to be so serious ttiat it was
decided to discontinue treatment."(Hazelbroek et al., 1991, p. 1061)- In this example,
cardiac/renal anomalies (developmental) were identified as antecedents of SOI. Postoperative
complication is a related factor that influences the stability of the neonate. Evidence of renal
insufficiency (instability) would likely present as derangements fkom physiotogical normal,
therefore SOI exists in this example. Treatment decisions are made taking into account the
SOI.
2. "Finally, in an attempt to control potential variations in admitting cntena and
illness severity for neonatal versus adult patients, we identified the subset of each ICU and
60
NlCU population with respiratory failure severe enough to require mechanical ventilation."
(h-feadow, Lantos, Mokalla & Reimshisel, 1996, p. 598). Respiratory fidure would likely
present as derangements of respiratory indicators. The consequence of respiratory instabiIity
is therapeutic intervention through mechanicai ventilztion.
3. ''When fidl-term neonates suffer asphyxia during labour or delivery, some may
develop hypoxic-ischaemic encephalopathy, with outcomes ranging fkom complete recovery
to death. Caregivers of these sick neonates have been searching for predictors of outcome to
faciiitate parental counse l i . and to provide appropriate levels of care that may include
withdrawal of therapy or initiation of neuroprotective strategies." (Cheung & Robertson,
2000, p. 262). This example identifies the antecedent to instability, mahinty of the neonate.
The stressfiil eventkomplication of labour is a related factor. The resulting derangements of
physiological indicators characteristic of hypoxia and ischaemia indicate the presence of
instability and thus SOI. Therapeutic intervention is discussed as a consequence of the
instability.
Results reported fiom the concept analysis will be summarized and discussed. Issues,
ideas, questions and comments arïsing from the study fïndings will be identified and explored
in the next chapter.
CHAPTER FOUR
Discussion
In this section issues, questions, and comments related to the study hdings are
discussed. Issues related to the description of the sample will be discussed fint as they have
an impact on the ridings fiom each of the study objectives. Each study objective wiLl then
be discussed followed by other issues including: verincation tests; lack of dennitions of the
concept; declining number of publications in 2000; subgroups among neonates; neonates,
chikiren and adults; empirical examples; and measures.
Description of the Sample
In this sample of 71 articles, the results showed that the concept, SOI in the neonate,
was used exclusively in the neonatal intensive care setting. The primary authors were
physicians, followed by nurses and mdtiprofessional groups. Research articles were the
dominant type of publication. Researchers studied groups of preterm neonates and groups
having both pretem and Wterm neonates about equdly. Two articles provided explicit
definitions of the concept. Of the 21 measues identined, 8 measures were used
predominantly (72%). These leading measures had simila. characteristics: (a) 7 of the 8
measures were directly derived fkom pediatric and adult measures, (b) 5 of the 8 measures
were developed by the sarne group of physicians, (c) the essential attribute identified in 5 of
8 measures was instability measured by physiologie indicators, and (d) clear definitions of
the concept were not evident in the articles describing the development of the measures.
The eight leading measures of SOI included: the SNAP (Richardson, Gray,
McCormick, et al., 1993), the S W PE (Richardson, Phibbs, et al., 1993), the S N A P VS
(Roblin et al., ZOûû), the SNAP II (Cheung & Robertson, 2000), the NTISS (Gray,
Richardson, McConnick, Workman-Daniels, et al., 1992); the TISS (CulIen et al., 1984); the
CRIB (INN, 1993); and the PSI (Yeh et al., 1984). The SNAP group included the original
SNAP and three variations of the original SNAP measure (Richardson, Gray, McCormick, et
al., 1993). All of the SNAP measures were derived from the PSI, a pediatric measure, (Yeh
et al., 1984) .and the -APACHE, an adult measure m a u s et al., 198 1)- The PSI (Yeh et al.,
1984) was used as a primary measure for infants and children in the literature until the SNAP
rneasure was published by Richardson, Gray, McConnick, et al. in 1993- m e r 1993, the
SNAP, developed specincally for neonates, was used as a primary measure. The TISS
measure was developed for the adult population (Cullen et al., 1974). The NTISS (for
neonates) (Gray, Richardson, McConnick, Worhan-Daniels et al., 1992) was derived ftom
the TISS. The majority of measures of SOI in the neonate used in this study have been
derived fiom pediatric and adult measures that have signincantly influenced the attributes,
antecedents, consequences and related factors identified in this study.
Connections existed among the authors of the eight leading measures. Richardson
and Tarnow-Mordi worked together collaboratively to publish research, review articles and
letters, sharing a sirnilar perspective regarding the nature of SOI. Other authors were linked
because they derived their measure fkom one another. Clearly, the results of this concept
analysis have been heavily ïnfluenced by a small group of physician authors.
The authors of these leading measures also shared a similar perspective with regards
to the nature of the concept. The PSI and the SNAP group of measures were based on the
essential attribute instability, as measured by physiologic indicators. Instability, as an
attribute, was derived directly fkom pediatric and adult measures. The physiologic indicators
used to measure SOI in CRIB also supported the existence of a physiologie component to
SOI. NZISS, derived h m TISS, was clearly presented as an indirect measure of SOI and
used indicators of therapeutic intervention to reflect SOI. This reflects heavily on the results
of the study, specificaiiy the m a i . finding of the essential attribute, instability, and the
support in the literature for therapeutic intervention as a consequeme of SOI.
The sample represented the perspective of a small group of physician authors. These
authors developed current leading measures of SOI in the neonate derived fiom pediatrïc and
adult measures. The essential attribute, hstabiiity, was used in the majority of these
measures. The results of the concept analysis were heavily influenced by the available
literature.
Major Study Fïndings
The overall purpose of this study was to develop a definition of SOI in the neonate
that captures neonatal characteristics and reflects a consistent view of the concept derived
fiom current neonatal literature. The following research objectives were addressed by this
study: (a) to detexmine the essential attributes of SOI, (b) to examine the antecedents and
consequences of SOI, (c) to ident* concepts related to SOI, and (d) to describe the uses of
SOI in the literature.
In the fist study objective, attrï'butes of SOI were identified. Instability was clearly
identified as an essential attribute of SOI. Other attributes, suffering and disability, although
identified in the literature, were less developed than instability.
The neonatal intensive care unit (NICU) was the context for SOI in every article
included in the study. Words used to describe this environment in the articles included
critical and acute implying that neonates admitted to this environment are at nsk for negative
outcomes. Discussions of SOI in the neonate in the literature included the terxns stabifity and
instability. These tenns represent two ends of a continuum and were sometimes used
interchangeably in the literature to characterize SOI.
To improve clarity in this analysis of the concept, it was important to select one of the
terms to represent this attribute. Stability represents the general goal of care in the NICU
however; the environment is characterized by change and fluctuation. Units are organized to
identiw and respond to signincant changes in the condition of the neonate. Indicators used to
refiect SOI focus on capturing abnormal results as opposed to evidence of nonnality and
stability. Studies tended to focus on changes in SOI and how they affect outcomes of care.
Instability was selected to reflect this attribute of SOI as it is more representative of the
NICU environment and meets the needs of health care professionals addressing questions of
prognosis, outcome and relationships with other concepts.
Logically, neonates are admitteci to the NICU to be assessed, monitored and
supported in order to manage andior rninimize the effects of instability. Authors of the PSI
(Yeh et al., 1984) discussed instability as a characteristic of SOI more clearly and in greater
depth than authors of subsequent measures derived fkom it (Le., S M ) (Richardson, Gray,
McCormick, et al., 1993). For this reason, instability did not emerge as an attribute in the
literature with the expected frequency. A possible reason for the minimal amount of
discussion written about instability was the declining use of the PSI for neonates aAer the
I98O7s. The PSI was developed for the pediatric intensive care environment (infants and
children) (Yeh et al., 1984) and was replaced by newer measures (SNAP) developed
specifically for neonates (Richardson, Gray, McCormick, et al., 1993). It is most likely that
the authors of SNAP transferred assumptions about instability as an attribute fiom the PSI
and did not make them explicit in articles about SOI.
The strength of the support for instability as the primary essential attnbute of SOI
came fiom its use in measures of SOI in the neonate. The PSI (Yeh et al., 1984) and the -
S N A P (Richardson, Gray, McComiick et al., 1993) were identified as leading neonatal
measures of SOI because they were used most fiequently in the iiterature (43%). The
physicians who developed these measures used instability to characterîze SOI and in doing
so, infiuenced the direction of the development of this concept.
The attribute, instability is commody m d e s t e d in the physiological domain and is
measured by physiobgical indicators (e-g., heart rate and respiratory rate). Instability is
reflected by the derangements nom physiological normal. Changes to the parameter either
above or below the normal range count towards the measurement of instability. The worst
physiological derangement for each indicator in a given time h e (i.e., the h e t 24 hours
following admission to a neonatal intensive care unit) is used to calculate the score. The
scores of al1 the indicators are summarized to reflect the SOI of the neonate. It is equally
important however, to reflect instability b y measuring the fluctuation of parameters both up
and down over time. Each neonate has a certain capacity to adapt to stresses based on their
maturity and development. The most serious instabilities can be indicated by prolonged
periods of derangement, fluctuating both above and below nomal such as with blood
glucose, respiratory and cardiac parameters. Aitemative approaches to measuring this
concept may need to be considered.
Almeida and Persson (1998) identifid sunering and disability to be attributes of SOI.
Almeida and Persson (1998) did not discuss these attributes in depth. Suffering and
disability were not identified in the data h m other articles included in the study. The
attributes proposed by Almeida and Persson (1998) represent a significant departue fiom the
essential attribute and other related factors identified. There was no evidence however, to
refute the inclusion of these attributes. This may reflect the ernergence of a new direction in
the development of the concept.
The second study objective was to i d e n t . antecedents and consequences of SOI in
the neonate. The antecedents identified were maturation and development. The consequence
identifled was therapeutic intervention.
Maturation and development are important neonatal characteristics that influence
SOI. Gestational age and birth weight have been used as proxy indicators of SOI (Almeida
& Persson, 1998; Richardson, Gray, McConnick, et al., 1993; Richardson & Tamow-Mordi,
1994; Wang et al., 1994). Congenital anomalies have also been identified as indicators of
SOI (Davies, 1995; Richardson, Tamow-Mordi, et al., 1999). One leading measure, CRIB,
incorporates birth weight, gestational age and congenital anomalies as indicators of SOI
(INN, 1993). These indicators were descnbed as risk factors added to physiology-based
measures to predict risk of mortality @anna et al., 1997; Richardson, Tamow-Mordi, et al.,
1 999; Stevens, et al., 1999). These characteristics of the neonate have been identified in the
selected literature and influence SOI in the neonate as antecedents.
Neonates having a low birth weight or extreme immaturity (gestational age) may be
more vulnerable to SOI and poor outcornes, however not ail neonates experience instability
as a consequence of having a low birth weight or gestational age. These patient
characteristics reflect issues of vulnerability and risk and the additive effects of several
factors that may contribute to SOI.
A neonate rnay have a serious congenital defect, yet it rnay not influence the SOI, as
rneasured by physiologic indicators. A congenitai anomaly rnay reflect risk of a more serious
condition and can predispose the neonate to an outcome that rnay be incompatible with Mie.
Instability rnay not be apparent in al i cases (e.g., minimal derangements of the partial
pressure of oxygen in an infant with a serious heart defect) (Davies, 1995; Perlman, 1998).
Current measures of SOI using physiologic indicators rnay not be sensitive to the influence of
congenital anomalies as an antecedent of SOI.
Therapeutic intervention was identified as a consequence of SOI in the selected
literature. Relationships were identified in the data between SOI and therapeutic
intervention: (a) therapy as providing assistance and support to the neonate (Avila-Figueroa
et al., 1998; Catlett et al., 1994; M i d et al,, 1999; Richardson & Tamow-Mordi, 1994;
R o b h et al., 2000), (b) therapeutic intervention as a response to instability of the neonate
(Holditch-Davis & Lee, 1993; Stevens, Richardson, et al., 1994), and (c) therapeutic
intervention as a proxy or indirect measure of SOI (Freeman et al., 1990; Gray et al., 1995;
Hazebroek, et al., 1991; Lee et al., 1995; Stevens, Richardson, et al., 1994).
The relationship, therapeutic intervention as a consequence of SOI, was found to be
prominent in the data. Many examples existed and facilitated the identification of this factor.
Physicians who developed the S N A P were also responsible for the development of the
prorninent NTISS measure (Gray, Richardson, McConnick, Workrnan-Daniels, et al., 1992).
This instrument was used extensively in the selected literature as a proxy for SOI, and
measured therapeutic interventions to reflect SOI.
The third study objective was to identiQ concepts related to SOI. The related
concepts identified were complication, capacity for behaviour and stress.
Complication was identifiai as a related factor to SOI, however the nature of the
relationship was unclear. Complication was used as an indicator of SOI using diverse
approaches: (a) fkequency of compl;'cations (Hefich Jones & Smyth, 1999), (b) single
complication used as a proxy measure (Lee et al., 1995), and (c) twenty of the most common
diseases and pathophysiological states were rated for SOI (Catlett et al., 1994; Holditch-
Davis, 1990). NSO, complication was identifieci as an indicator of fiinctional status
(fünctional status was identified as a related factor to SOI) (Stevens et al., 1996).
Minimal available data and different ideas about the nature of the relationship were
expressed but few explained the ideas in sufficient depth to clarify how complication is
related to SOI. Indicators of complication were used in 5 of 21 measures in combinations
with indicators from other factors such as maturation/development, physiology and
therapeutic intervention. Discussion did not explain how indicators of complication reflected
SOI.
Capacity for behaviour was discussed in the data primarily as a response to SOI or as
having a relationship with SOI. Limited discussion of this factor was present in the articles.
Based on the available data, capacity for behaviour, was not considered to be an attribute or a
consequence of SOI, but a related factor.
Although capacity for behaviour was discussed as a response to SOI in the select
literature, the nature of the relationship between capacity for behaviour and SOI remains
unclear. The lack of data and inconsistencies related to the use of capacity for behaviour as
an indicator of SOI contribute to this lack of clarity. Capacity for behaviour was used as an
indicator of SOI in the Apgar score (Apgar, 1953). The Apgar score was the only measure of
SOI in the neonate identified in this study that incorporated indicators of behaviour (Apgar,
1953). The Apgar score measures appearance, puise, grhace, activity and respiration at one
and five minute intervals following birth (Apgar, 1953). The Apgar score was used only
once on its own in the study articles, however it was incorporated into several measures of
SOI that were used more fiequently including the SNAP f E, SNAP II and NICHD (Pollock
et al., 2000; Richardson, Phibbs, et al., 1993; Richardson, Tarnow-Mordi, et al., 1999). As
the Apgar score was incorporated into some of the primary measures, there appears to be
some recognition that behaviours may reflect SOI.
It is difficult to iden* reasons why capacity for behaviour was discussed and used
in some measures in a limited capacity in the selected articles. In the articles, 10 of 71
discussed behaviour in relation to SOL This could have been infiuenced by two factors. The
first factor relates to an overall reliance on physiological indicators in the sample of articles.
Physiological indicators of SOI have a long history of acceptance and are considered
objective measures that are reliable and valid. Behavioural indicators may not yet share that
same acceptance and widespread use, despite the development of objective, reliable and valid
measures for neonatal pain over the 1s t decade that have used indicators such as cry
characteristics, facial actions, body movements and posture (Stevens, Johnston, et al., 1994).
Also, infant behaviour theory in relation to stress has been rehed and indicators have been
identified (Als, 1983). Interventions such as developmental care have been applied in the
neonatal intensive care environment in response to behavioural indicators of stress (As,
1983). Behavioural indicators have been extensively developed and used over the last decade
but have not been considered or applied in the mesurement of SOI with the exception of the
Apgar score (Apgar, 1953).
70
It was noted on review of the data set for capacity for behaviour that 8 of the 10
articles that discussed behaviour in relation to SOI were authored by RNs and
multiprofessional groups authored 2 of the 10 articles. This second factor uidicates that
overall, physician authors did not discuss behaviour in relation to SOI. The fact that the
Literature has been dominated by a smaîi group of physicians may have indicated a bias
towards the use of traditional objective indicators (e-g., physiological). Alternatively, there is
evidence that many of the objective indicators for behaviour may have only been refined in
the last decade through the development of infant behaviour theory and its application (Als,
1983). The resulting concurrent development of the leading measures of SOI in the early
1990s and objective indicators of behaviour may have led to the development of SOI
measures that are reliant on physiological indicators.
It is unclear how behaviour, physiology, and SOI are linked in neonates. Evidence
exists that capacity for behaviour is affeçted by SOI. Use of behaviour as an indicator of SOI
has been minimal in the literature. Although capacity for behaviour was discussed in the
select literature, the nature of the relationship between capacity for behaviour and SOI
remains unclear. The use of physiological indicators to reflect SOI has dominated recent
literature (1 990-2000). Generally, this lack of understanding of the relationship between
physiological and behavioural indicators exists between other concepts as well including pain
and stress.
The category stress was represented by a very smail amount of data. Petryshen &
Stevens (1995) suggested that degree of stress could be evaluated using physiologie stability,
as measured by SNAP. In the second excerpt, Stevens, Johnston, et al. (1994) comected
stress to neurologicai disorganization, as indicated by cry characteristics. They identified
that cry characteristics also reflected the SOI of the neonate. This view links the idea of stress
with SOI as a related factor. These authors petryshen & Stevens, 1995; Stevens, Johnston, et
al., 1994) suggested that instability (SOI) and neurological disorganization reflect stress in
the neonate. Other articles did not discuss this association. The association suggested
between SOI and stress is clear in a few of the articles included in the study; fbther
elaboration of these ideas was not fond in the lïterature-
In the fourth study objective, uses of SOI were identined. The relevant purpose of the
concept is refiected in its use and its use influences the development of the concept. SOI has
been used in research independently and in combination with other risk factors to predict
mortality. It has been used as a dependent variable in studies of clinical outcomes. Many
researchers have been concerned about the confounding e&t it may have on experimental
and control groups of neonates and have employed various strategies to control or adjust for
its effects. Some researchers have shown interest in the relationsbips that may exist between
SOI and other variables. Authors also descnbed potentid uses for the concept including
supporting decisions regarding the ailocation of staff and resources, cornparisons of hospitals
and practice patterns, and prognostic systems for decision support.
As relationships between SOI and other concepts become better understood, SOI will
likely retain its usefùlness in neonatology. Based on its contribution to the study of outcomes
and thus support for clinical decision-making in addition to the potential to support economic
and administrative decision-making, SOI will likely continue to develop and evolve as a
concept. The definition of SOI in the neonate and the conceptual mode1 represent a tentative
and guiding view of this concept, heavily influenced by characteristics of the available
literature.
Other Issues
Verification Tests
The purpose of the verincation tests was to check the rigor of the process of
categorizing data. Issues associatecl with these tests were identined during the study
including: (a) extraction and organization of data, (b) calculation of level of agreement, and
(c) concurrent collection and analysis of data, These issues are addressed and
recommendations for improving the process of checking the categorization of data are
O ffered.
These tests provided the opportunity to consult with experts in neonatal care. The
experience of working towards achieving a level of consensus with the practitioners involved
meeting face to face and discussing each category of data and how the data related to the
category label. Consensus was achieved through thoughtful discussion and the sharing of
meaningful insights about the nature of the concept in the neonatal population, and the
meaning conveyed in the data The process of improving the levels of consensus revealed
several areas that required-revision. Clarification was necessary in two main areas: (a) some
of the pieces of data were too lengthy, and @) some of the pieces of data were too complex,
(Le. included more than one idea that might be used to classify the data). The first issue was
resolved by examining the data more crïtically and by reducing the pieces of data extracted
as much as possible. The second issue was addressed by underlining the most important idea
in each piece of data to indicate which idea was being used to classw the data-
As the verification tests were diffèrent fkom each-other in this study, the percentage of
agreement achieved with each practitioner could not be compared. The strength of the
results of these tests would be improved and would provide better evidence of rigor if the
following recommendations were hcorporated: (a) ensuring the percentage of agreement
was recalculated following discussion between the student and practitioner to accuately
reflect the consensus achieved, and (b) having more practitioners engage in the tests. Having
more practitioners participate in the tests would d o w the percentage of agreement for each
test to be compared between the practitioners. The level of agreement would be reported as
an average for each test.
Some authors (Rodgers, 1993a) have expressed concems that early
examination/analysis of the data before completion of the data collection process may
idluence the fidings in concept analysis. Rodgers (1993a) has suggested that premature
conclusions may be a consequence of analyzing data concurrently with data collection.
Based on this suggestion, condueting this verincation test to support the rigor of the analysis
may well have influenced the identification and/or labeling of the attributes. The effect of
early analysis of the data on the results of the study was likely minimïzed by the following
factors: (a) the amount of data categorized for the purpose of verifkation was minimal
(14%) relative to the total amount of data included in the analysis, and (b) categonzation of
data constituted only part of the analysis procedure.
Lack of Definitions of the Concept in the Literature
Definitions of the concept, SOI, were rare in the selected literature as were conceptual
fiarnework sections that discussed SOI. Possible reasons why defkitions of the concept were
not included in articles written by physicians during this time frame include the belief that
the concept, SOI is self-evident. This view is clearly expressed by Richardson, Tarnow-
Mordi, et al. (1999), authors of leading measures of SOI in the neonate, 'Tlhess severity is an
instinctive, self-evident concept; the challenge has been how to operationalize its
measurement." (1999, p. 260). This belief is also supporteci by the foilowing quotation,
"'Akhough severity of illness is a f d a r medical concept, it is sometimes difncult to
assess."(Pollack et al., 2000, p. 1052). These authors focused primarily on issues associated
with the development of measures as development of a conceptual dennition was viewed as
less important.
Declining Number of Publications in 2000
The year of publication reflected interest in and use of the concept by health care
professionals. The number of articles meeting the selection cnteria showed a steady increase
over the eleven-year period studied for this thesis. An exception to this observation was a
slight drop in the number of articles in the year 2000. There are no clear explanations for this
decline. This might be explained by a 1ag in publishing. At this time, the student is aware of
a large research study completed in 1997 that compared different measures of SOI (Corcoran,
Whyte, Thiessen, Lee & The Canadian NICU Network, 1998; Lee, Corcoran, Whyte,
Thiessen & The Canadian NICU Network, 1998; Richardson & Escobar, 1998). These
authors have presented results fiom this study at confierences but the student has not been
able to identifL auy published articles (Corcoran, Whyte, Thiessen, Lee & The Canadian
NICU Ne twork, 1 998; Lee, Corcoran, Whyte, Thiessen & The Canadian NICU Network,
1998). Abstracts 6om these conference presentations were published but were not included
in this study, as they did not contain sufticient discussion of SOI (Corcoran et al., 1998; Lee
et al., 1998). Richardson & Escobar (1998) identified additional international groups that are
currently conducting neonatal research into SOI that have not yet published their work. The
trend over the eleven-year period indicates that SOI is considered an important variable and
continues to be studied by health professionds. The drop in the number of articles published
in the year 2000 is most likely a chance hding that is not signiscant or clinicaily important.
Subgroups Among Neonates
Two groups of patients were studied equaliy in the selected literature, the preterm
neonate group, and the pretedfülltemi neonate group. Roportionately, more preterm
infants were studied in the select literature, as preterm infmts were part of both groups. It is
possible that the preterms have been studied or discussed more fiequently by authors because
they are believed to be more vulnerable to SOI based on the influence of immaturity
(Holditch-Davis, 1990) and thus SOI may be considered a more relevant concept for this
P U P -
Neonates, Children, and Adults
Neonates, children and adults share the essential attribute of SOI, instability- This
essential attribute of SOI in the neonate has been derived directly fiom SOI in children and
adults. Authors of the leading neonatal measures derived the essential attribute directly fkom
pediatric and adult measures. Differences between neonates, children and adults that were
noted fkom the fïndings of this study include the antecedents, maturation and development
that are clearly characteristics unique to the neonate.
Empirical Examples
Empincal examples of SOI were extracted fkom the literature to identify relationships
among SOI, essential attributes, antecedents, consequences and related factors and to provide
justification for their selection. These examples illustrated circumstances that comrnunicate
the nature of SOI in context. Each of the examples provided showed instability of the
organism preceded by an antecedent patient characteristic. instability was influenceci by at
least one related factor and resulted in a treatment response (Le., intervention or withdrawal
of treatment).
No ideal example of the concept exïsts (Roâgers, 1993a). Some methoch of concept
analysis recomrnend the construction of an ideal example to cla- exactly what the concept
is (Walker & Avant, 1995). In addition, it has been suggested that examples of what the
concept is not (contrary cases) and examples that are sirnilar but not quite the same
(borderline cases) be constructed (Walker & Avant, 1995). The use of constructed cases
increases the nsk of introducing bias to the analysis of the concept* In this study, examples
were identified fiom the selected literature and discussed in terms of their similarity to the
findings of the concept analysis (attributes, antecedents, consequences and related factors).
The expectation of a perfect match was not in keeping with the conceptual foundations of the
study. Therefore, the examples illustrateci varying degrees of fit with the proposed dekition
of the concept and findings of the study.
Measwes
A large nurnber of measures of SOI were used throughout the selected articles. The
most fiequently used indicators across ail measures were physiology-based however, most of
the measures were composite scores and included indicators fiom at least one other factor
related to SOI. The CRTB score (INN, 1993), for example, was composed of a combination
of physiological indicators and maturationaVdevelopmenta1 indicators (birth weight,
gestational age, and congenital anomalies). The data were organized to show how most of
the measures, though they rely heavily on physiology-based indicators, include indicators
fkom factors that are related to SOI as antecedents, consequences or related factors (see
Appendix G). It was beyond the scope of this study to examine these leading measures in
terms of their psychometric properties - validity, reliability, and intemal structure - which
may ultimately provide more understanding of SOI and the relationships between types of
indicators.
CHAPTER FIVE
Summary, Implications, and Conclusions
Summary
SOI in the neonate is a concept that has been used almost exclusively in the context of
the NICU. Physicians conducting research have dominated writing on this topic. There is
evidence that nurses are using this concept although to a lesser extent than physicians.
Nurses have used SOI primarily as a clinical outcorne. The neonatal SOI literature bas been
dominated by five mesures that have a l l been derived fiom pediatric and adult measures and
are based primarily on instability of the neonate manifested by physiologic uidicators.
Suffering and disability were also identified as attributes of SOI. Explanations of how these
attributes relate to SOI were underdeveloped and unclear. SuBering and disability may
represent newly emerging attributes in the development of the concept. Most composite
measures have incorporated indirect indicators of SOI (e.g., antecedents, consequences and
related factors). Some inconsistencies were found between the conceptualization of SOI and
the composition of indicators in the measures being used.-Different combinations of
indicators were used reflecting instability, maturation/development, therapeutic intemention,
complications and capacity for behaviour.
This study identified that instability is the essential attribute of SOI. Maturation and
development was an antecedent. Therapeutic intervention was a consequence. Related
factors included complication, capacity for behaviour and stress. A definition of the concept
was developed to reflect the selected neonatal literature (1990-2000). A conceptual mode1
was developed to provide a visual display of the relationships identified in the concept
analy sis.
hplications
Conceptual Mode1
The conceptuai mode1 provided a visual display of the relationships between SOI and
the attributes, antecedents, consequences and related factors that define it. The relationships
identified in the mode1 were supported to varying degrees in the literature by: definitions of
the concept, examples, discussions of dimensions and the measurement of SOI. The
identification of instability as an essential attribute and therapeutic intervention as a
consequence was supported by the development and prominent use of several leading
measures of SOI in the study articles (Gray, Richardson, McConnick, Workman-Daniels, et
al, 2992; Richardson, Gray, McComick, et al., 1993; Yeh et al, 1984). The attributes
suffering and disability and the related factors, complication, capacity for behaviour and
stress were not well developed. Further, the relationships between these factors and SOI
were often unclear and/or conflicting in the literature. Suffering and disability, for example,
were identified as attributes of SOI in only one article, and explanations of how this
dimension reflected SOI and how it might be measured in neonates were insufficient.
Professionals other than physicians such as nurses and multidisciplinary teams oAen wrote
about and discussed these factors (suffering, disability, complications, capacity for behaviour
and stress) in the context of other nmnatal issues such as the relationship between SOI and
pain (Stevens, Johnston, et al., 1994). This discussion implies that new uses for SOI may
exist and require the development of other aspects of SOI.
Capacity for behaviour was identifieci in the concept anaiysis of SOI as a related
factor. Several nursing articles nom the selected fiterature provided evidence that a
relationship exists between capacity for behaviour and SOI as a response to SOI (Holditch-
Davis, 1990; Stevens, Johnston, et ai., 1994). Behaviour was not weil supported as an
attribute of SOI as it was used minimaiiy as an indicator of SOI in the selected articles and
was not clearly explained by the authors. Nurse authors showed significant interest in this
relationship. As infant behaviour may reflect their response to instability, M e r review of
neonatal behaviour theory (Als, 1983) may provide M e r insight into the natute of the
relationship between SOI and capacity for behaviour.
Most measures of SOI in the neonate idenaed in this study are composites of both
direct and indirect indicators that reflect the many dimensions of the concept. These
measures reflect multiple dimensions of SOI that are related to the concept as antecedents,
consequences and related factors. Without a clearer understanding of how suffering,
disability, complication, capacity for behaviour and stress are related to SOI, the accuracy of
these measures in reflecting SOI is questionable. However, composite measures may be the
best avenue to capture the complexity of this concept.
Most of the measures have used indicators fiom maturationldevelopment
(antecedent) and therapeutic intervention (consequence), to reflect SOI, such as in the CRIB
score that combines indicators fiom an attribute (physiologie instability) and fiom an
antecedent (maturation/development). The fïndings of the concept analysis are not consistent
with the application of indicators in current measures of SOI. The use of indirect indicators
fkom antecedent, consequence and related factors has infiuenced the measurement of SOI
disproportionately (see Appendix G). Understanding of the antecedent, consequence and
related factors needs to be developed to better explain the relationships and to support
development and use of indicators and potential composite measures that best reflect the
concept.
The potential linkages between SOI and suffering, disability, complication, capacity
for behaviour and stress require M e r review in the literature and elsewhere that is beyond
the scope of this study.
Clinical Nursing Practice
Analysis of SOI has provided a beginning understanding of the concept, its essential
attributes, the various factors that influence it, and its consequences. This study has provided
an opportunity: (a) to recognize the concept in clinical nursing practice, (b) to iden-
antecedents, consequences and factors related to SOI, and (c) to detexmine potential uses for
the concept in clinical nursing practice.
The importance of SOI to clinical practice was clearly identified in the concept
analysis. The assessment of SOI can be recognized in clinical nursing practice as the routine
monitoring and physiological assessment of organ systems in the neonate. Monitoring and
assessment activities form an integral part of nursing practice in neonatal intensive care
settings. Assessrnent of the neonate is important in clinical practice to identifjr subtle
changes in SOI of the neonate that may reflect more serious outcomes, such as bacteremia
(Beck-Sague et al., 1994; Freeman et al., 1990). Many different relationships between SOI
and neonatal outcomes were evident in the selected literature such as the testing of SOI as a
predictor of specific morbidities and mortality (Escobar et al., 1997; INN, 1993; Perlman,
1998; Stevens, Richardson, et ai., 1994).
This analysis identifieci instability as an essential attriiute of SOL Prirnary measures
of SOI identified in the study articles incopporated multiple physiologic indicators of
instability fiom seven of the main organ systems including cardiovascular, respiratory,
neurologic, hematologic, rend, gastrointestinal and metabolic. Derangements of those
physiological indicators, both above and below nomial ranges for neonates reflected
instability (Richardson, Gray, McCormick, et al., 1993; Yeh et al., 1984). SOI is assessed in
clinical nursing practice by measuring instability. Many physiologic indicators are
comrnonly incorporated into clinical assessments of the neonate by nurses (Richardson,
Gray, McCormick, et al., 1993; Yeh et al., 1984). Clinically useful assessrnent of SOI can be
achieved by selecting and monitoring only those physiologic indicators specific to the patient
(Le. type of disease and associated risk of organ system failure). Early identification of SOI
(instability) by nurses and an understanding of how changes in SOI are associated with
specific outcomes are necessary to select and apply appropnate interventions in a timely
marner. Neonatal nurses currently rely on physiological measurements in their practice to
monitor the progress of the neonate towards a specific outcome and to indicate the need for
intervention.
Although nurses may be able to identify a relationship between SOI and neonatal
outcomes in clinical practice, the interplay of other factors with SOI and outcome may not be
as readily identifiable. Analysis of the concept helped to identify factors associated with the
concept, such as antecedents, consequences and related factors, which rnay infiuence the
degree of SOI and possibly neonatal outcomes. Neonatal characteristics including
maturation (e.g. gestational age and birth weight) and development (e.g. congenital defects)
were identified to be antecedents of SOI in the analysis. Gestational age and birth weight
were fiequently used as risk factors dong with SOI to predict negative outcomes such as
death (INN, 1993; Richardson, Gray, McConnick, et al., 1993; Richardson et al., 1998).
Also, gestational age and birth weight were fiequently used as indicators of SOI (Tarnow-
Mordi, Mutch, Parry, Cockburn, & McIntosh, 1995; Richardson, Shah, et al., 1999). From a
clinical perspective, gestational age and birth weight are considered important risk factors
that reflect generally, the infant's potential for a negative outcome. The relationship between
these neonatal characteristics and SOI must be considered when selecting interventions to
address specific outcomes.
Therapeutic intervention was identified in the concept analysis to be a consequence of
SOI. The number and type of interventions received by the neonate were thought to be a
response to the SOI. Some indirect measures of SOI, such as the NTISS, PM DRG, and
NMS scores, incorporated indicators of therapeutic intervention (Gray, Richardson,
McCormick, Workman-Daniels, et al., 1992; Minde et al., 1983; Schwartz, Michelman,
Pezzullo, & Phibbs, 1991). In the NICU setting, it is an expectation that nurses will
anticipate and i d e n a changes in the stability of the neonate and are prepared to respond to
them. Assessrnent and identification of SOI result in the planning and delivery of
therapeutic intervention. Interventions or therapies are intended to support the neonate. The
nurnber of therapies may indirectly reflect SOI, as therapy reflects the degree of support
required by the neonate to maintain or achieve stability.
The related factors identified in the concept analysis kluded complication, capacity
for behaviour and stress. The nature of the relationship between SOI and complication
lacked clarity in the selected literatwe. Conflicting ideas existed, making it difncult to
understand how this related factor rnight influence SOI therefore; no specinc
recommendations for clinical nursing practice could be made. This rnay represent an area for
M e r study fiom a clinical perspective.
The association between stress and SOI in neonates received minimal attention in the
literature reviewed. RN authors suggested that SOI and neurological disorganization
reflected the degree of stress experienced by a neonate (Petryshen & Stevens, 1995; Stevens,
Johnston, et al., 1994). Behavious such as cry characteristics were used as indicators of
neurological disorganization and stress (Stevens, Johnston, et al., 1994). As stress and SOI
rnay be closely linked, behaviourai indicators rnay prove usefhl in reflecting SOI in clinical
nursing practice. Much has been written on the identification of stress in the neonate through
the work of Als (1983). Nurses have used behavioural indicators to idente stress and have
responded to reduce neonatal stress by implementuig developmental care strategies (AIS,
1983). Increased awareness of associations between behaviour, stress and SOI by nurses
rnay reinforce the importance of using behavioural assessments in monitoring and treating
neonates. The implications for clinical nursing practice rnay be to increase nurses' awareness
of factors that rnay inniience or be influenced by SOI in the neonate including gestational
age, birth weight, congenital anomalies, therapeutic intervention, capacity for behaviour and
stress.
Recognition of SOI in clinical nursing practice and kmwledge of the potential
associations between SOI and antecedents, consequences and related factors rnay help nurses
begin to incorporate research evidence into theu clinical practice. Many uses have been
identified for SOI in the selected lïterature and new ones could be identifïed in clinical
nursing practice. SOI has been used to provide information about administrative issues such
as workload planning and resource use in NICUs (Almeida et al., 1991; Richardson, Gray,
McCormick, et al., 1993; Richardson & Escobar, 1998; Schwartz et ai., 1991). SOI c m also
be used as an outcome to monitor the effects of a chosen intervention (Lee et al., 1995;
Petryshen & Stevens, 1995; Petryshen et al., 1997; Stevens et al., 1996)- Measurement of
SOI could reflect the ameiioration of stress for inf'ts receiving various interventions
(Fetryshen & Stevens, 1995). SOI has been used as a clinical outcome by nurses to compare
conventional versus developmental care (Stevens et al., 1996). 0 t h studies looked at the
relationship between SOI and complications common to the NICU such as bacteremia (Beck-
Sague et al., 1994; Freeman et al., 1990; Gray et al., 1995). &O, relationships between SOI
of the neonate and the responses of parents to the neonate were investigated (Kratochvil et
aI., 199 1 ; Zahr & Cole, 199 1)- Nurses assess neonates to anticipate problems or issues, to
respond to those problems by selecting and implementing appropriate interventions and to
achieve or maintain positive outcomes. Awareness of how SOI has been used in research
may influence decision-mahg and choice of intervention for nurses in clinical practice.
Measurement of SOI remains a challenge in the neonatal population. Leading
measures of neonatal SOI have been denved fkom children and adults (Knaus et al., 198 1;
Richardson, Gray, McCormick, et al., 1993; Yeh et al., 1984). Several leading measures rely
primarily on large sets of physiologic indicators that may not be practical for clinical use (see
Appendix F) (Richardson, Gray, McConnick, et al., 1993; Yeh et al., 1984). Other leading
measures use a mix of direct and indirect indicators fiom maturation and development,
therapeutic interventions and instability that are not aU supported by the results of this
analysis as essential attributes (Gray, Richardson, McConnick, Workman-Daniels et al.,
1992; INN, 1993). The development o f a reliable, valid and clinically usefiil measure of SOI
would be beneficial.
Knowledge and understanding are to be gieaned fkom M e r use of the concept in
clinical nursing practice and will influence development and clarification of the concept. The
results of this study may provide beginning support for whzt nurses already h o w about
complex interactions in the neonatal intensive care setting and facilitate the incorporation of
evidence-based practice into clinical nursing practice. Improvements in neonatal care by
nurses are supported by the development of evidence-based practice related to SOI and
outcornes.
Research
The nature of SOI in the neonate was examined in this study. The essential amibute,
other attributes, antecedent, consequace, and related factors were identified and labeled.
Finally, a definition of the concept was developed. The findings of this study were heavily
influenced by the available liteninire including the type of author, measures used and type of
publication- Some of the inconsistencies between measurement of the concept and
associated dimensions may reflect: (a) a concept that has not yet been M y developed, (b) the
changing needs of neonatology as a discipline, andior (c) the differing needs of the individual
disciplines within neonatology including nursing. Further research into SOI is necessary to
support the evolution of the concept. Findings of the concept analysis have resulted in the
following recommendations for fiiture research:
1. Further refinement of the concept including: (a) validation of the findings of this
study using focus groups of experts in neonatal care and addressing attributes, antecedents,
consequences, related factors and uses for the concept in neonatal care; (b) use of qualitative
methods such as participant observation as suggested by Schwartz-Barcott & Kim (1993) to
study the concept in the NICU setting, to integrate the results of the literature review with the
results of qualitative methods and to determine whether the hdings support the presence and
frequency of the concept; (c) review of related neonatal literature for evidence of
relationships between SOI and each of the following factors; complication, capacity for
behaviow, stress and s u f F e ~ g and disability; and (d) secondary anaiysis of the study
hdings to isolate nursing articles, to identify uses for SOI in neonatd nursing practice and to
identiQ specifk research issues that might be addressed using SOI. These activities would
provide a beginning point to: (a) validate the hdings of this study, (b) identifjr what issues
nurses carhg for neonates have addressed using SOI and whether any limitations to its
application exist and (c) clarify the relationships between SOI and each of the following
factors; complication, capacity for behaviour, stress, suffiring and disability.
2. Development of an operational definition and measure of SOI in the neonate
including: (a) examination of the psychometric properties of curent leading mesures of SOI
in the neonate, and @) comparison of indicators used in leading mesures in relation to
indicators reflecting the attributes identified in this study. Further research will r e h e the
concept, validate the fkdings of this study and facilitate the identification of appropnate
indicators that reflect the complexity of SOI. The development of an accurate measure that is
clinically useful to nurses will support the study of neonatal outcomes research in general and
facilitate identification of other research questions that may be addressed using this measure.
Conclusions
Based on significance, importance and use in neonataî care, SOI in the neonate is a
significant concept for nursing. Clinical assessments by nurses are intended to identify SOI
in the neonate. Nurses select and apply interventions to effect positive change in the
outcomes of neonates. Nursing decisions are made based on research evidence that includes
lmowledge of the relationships between SOI and outcomes. Understanding and rneasurement
of SOI is cntical to the study of neonatal outcornes as a source of variation in achieving
outcomes and as a risk factor to negative outcornes.
The analysis ofthis concept has provided nurses with a beginning understanding of
SOI, its attributes, antecedents, consequences and related factors. Some aspects of this
concept remain less clear and require M e r examination including complication, capacity
for behaviour, stress, suiTering, and disability- There is a need to review other sources of
Iiterature and to validate the study results using alternative methods such as focus groups and
participant observation in order to M e r clariq these relationships with SOI.
In tems of cluiical nursing practice, there is clearly a need to tailor physiologic and
behavioural assessments reflecting SOI to risks specific to the individual neonate.
Recognition of SOI in clinical nursing practice will begin to identiQ other potential uses of
the concept for nurses.
The use of composite measures of SOI in the neonate was prominent in the study
literature but rationale for inclusion of indicators representing different dimensions of SOI
was not always clear. Despite this hding, composite measures are likely to be the best
direction for measure development based on the complexity of the concept. Finally, efforts
directed to M e r refinement of SOI will continue to move us towards the development of a
measure of SOI in the neonate that will reflect current use of the concept and will identiQ the
concept, relationships between outcomes and SOI and new uses for SOI that are important to
neonatal nursing care and will ultirnately improve patient care.
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(LOI@ wqisn8Is Oulunu lW!P w = d s U! S y i O w ~ W
I ~ I I O J W O admm lldde p dopep 'pales
01 MOY WUepnbr 43-1 01 pasn Sem )I 'sonintn h o q i
8ulEinu jo sqJw a ut esn J O ~
Norris (1982) Walker & Roâgrn (1993) Schwritz-Barcott Chlnn 6 Avant (1995) & Klm (1983) Krimer (1991)
1. IdenUV the conœpt 8 1. Selecl a concept 1, ldentify concept of Theorethl Phasa 1. Select a concept obsenreldescribe the phenomenon repeatedly also from other disciplines 2, Systematlze lhe observations and descripUons 3. Derive an operational definitlm ol the concept 4. Pmduœ a modal of the =Qmpt 5. Formulate hypoaisaes
2.ûctermine the alms or purposes of the analysls 3. Dlxover al1 uses of the concept 4, Delermlne the defining anributes 5, Construct modei case 6, Construû borderilne, related, invented, contrary U ilkgltimate u w s 7, Identify antecmdants 6 conquences e, MW «nptrlu~ wremlta 1. IIdearr(e91 2. Ibmtive procsrr 3. Umdexamplerto # I U S U ~ ~ 4. IdenübUon d amdt0)ons S,Crea!a opmtionrl definltk 6, IW1îy Mat m œ p b a n change over Umdnot datk
Walker U Avant however, dld idenlify Ihat conœpls dirnga owr tlrm (p.37) - thmfors philobophical vbw LI undea
2. Potrntkl for marcher bias in devekplngAdsntifying
interest 2. Identify surrogate terms 3. ldentlfy sample for data collection 4. Ideritify the attributes of Ik iencept 5. ldentiîy mferencrn, anteosdents 6 c o n q w n œ i of amœpî 8, ldentify reletad concspts 7, ldontify a mdai ciw 6, Conduci inlordibclpliniry 4 temporal com(Plrlrom
1, A d w l nmthod Vary ahnile io Wilker 4 Avrnt(lfiBS), uncîear h w phi loso~ki l unôefpinnlng8 chingo the appliciblond~mahod rpill hom the dinsrericas In use of exrmpka 2, Sampllng of data may cause researchcr to omiî data cm-d major workm may rmke the data more wunageable, howwsr trmb W p b of data a8 que l which ir probkmitic
1, Select a concept 2. Search the Ilterature 3, Deal with meanlng 8 measuremenl 4, Choose a worklng deflnitio Çleldwork Phase I, Set stage 2. Negothte anliy 3, Seled cm08 4. ColW 6 anaiyze daîa Finil Anrlytlcol Pham kMi~hing, working and writlng up üm ïindings,
2. Ciariiy purPo& 3. ldentify data sources mode1 cases, lilerature etc 4, Explore context L values 5, Fornulate criteria
1, Sekrrstopa 2, Includm Identifylng exemple8 wiih oîher data IOUlw8
3, I ~ t l f k i impwlrnœ of MC&! cunw 4 v i l w r in the formation of meanhg 4. Criteria are bnhtive U guiding in nature to dlbr trom other InrtPna, 1, Sîeps- dlIcuukn v«y genoral 2. Potentlal for mearcher Mar In developlnglidantifyin~ cusrtokusedfoiexunplo 3, Ootr not apc@ whrther concept can chanw ovsr tlm
cases Io be used for exampies
Appendix B
Computer Database Search
Articles were selected for review fiom Medhe, Healthstar, Cinahl, Cancerlit, and
Embase databases using search criteria based on the MeSH system of classification. The
following MeSH terms were used to search the five databases:
1. Explode infant, newbord or neonate.mp.
2. Expiode severity of m e s s index/ or severity of illness.mp.
3. Combine 1 and 2 (intersect)
4. Limit to English language and year 1990 to 2000.
Appendix C
Record Book Sample
ProbIems or issues that shodd not be addressed during the data collection W o r
analysis were identified and recorded in a record book. Information relating to the; (a)
inclusion~exclusion of data, (b) methodology, (c) analysis, and (d) ~e~awareness of the
student (personal acknowledgment of potential biases, thoughts and opinions of the student)
were recorded in four separate record books and were set aside for consideration following
comple tion of the analysis. For example, serendipitous kdings were acknowledged and
considered following data analysis. The following examples are fkom each of the four record
books:
1. InclusiodExclusion of Data. Although article 'X' mentions infants in its patient
population, no fkther discussion regarding severity of illness was included and the severity
of illness measure used by the researchers was an adult measure. This article was not
included in the analysis. Although the PRISM measure for severity of illness was developed
for children and infmts, the measure did not isolate neonates in the measure therefore; this
article was not included in the concept analysis.
2. Methodology. A recommendation for orga-g the study method was
discovered. It suggested that the researcher should not draw any conclusions fiom the study
until d l the data is collected. Analysis should not take place simultaneously with the data
collection.
3. Analysis. It was discovered during the andysis that most of the literature written
on SOI in the neonate has been developed h m the same group of physicians. This should
be included in the discussion section of the thesis.
4. Self-awareness of the Researcher. The student has been spending a lot of time
trying to decipher what the author meant by vague or confûsing statemenh about SOI. It is
likely that if the student guesses what the author is m g to Say, bias will be introduced into
the study.
A souru
ID No.
- 6
rearc )ubIic ation
-
-
E Concept- ual Defn lmpl or Explicit
Appendlx D
Data Collection Form
F Conceptua Definition Dimensian!
H Operaüonal
Definition
I Name of Measun andior Indicators
J Concept Usage
K Description of Context
L Ternis used to refer to
SOI -
Appendix E
Reference List of Ineligible Articles
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,Measures and hàicators of Severi& of Illness
Name of Measure Ab breviation hdicators
Appearance, Pulse, Grimace, Activity, Respiration
Clinical Classification Systern
Clinical Risk Index For Babics
International CIassification of Diseases (9h ed-)
Diagnosis Related Groups
Pediatric Modified Diagnosis Related Groups
MedisGrps Severity Classification System
Neurobiologie Risk Score
APgar Score 1 to 3 at 1 minute and 5 minutes Color, heart rate, reflex imtability, muscle tone, respiratory effort.
CCS
DRG
PM DRG
Class I Patients were not admitteci to the [CU Class CI Patients were physiologically stable and were admitteci to the [CU only for monitoring or observation. C la s ïIï Patients were physiologically stable requinng intensive care nursing and monitoring. Class iV Patients were unstable needing fiequent assessrnent and interventions by [CU physicians and nurses-
Birth weight, gestational age, min Fi02, max Fi02, max Base excess, congenital anomalies
One major category devoted to neonates (MDC-15) Seven smailer categories for neonates based on death, transfer, birthweight, prematurity, major problerns and respiratory distress syndrome.
One major pediaûïc modified diagnostic category indudes al1 neonates younger than 29 days. Forty-six srnaller categories for neonates based priman'ly on birthweight, postnatal age, or minor/ major problem, deaths, transfers, and duration of mechanical ventilation.
Medical illness grouping system measures case mix and case mix severity clinicatly based approach to classiwng hospital patients at admission to answer question how sick is the patient? 500 key clinical findings (KCFs) including laboratory, radiology, pathology, history and phfical examination.
NBRS 13 items - Apgar score, Pa02, ventilation, blood pH, apnea, hypotension, PDA, seizure WH, PVL, infection, hypoglycemia, bilimbin
Revised NBRS Apgar, PaO2, ventilation, blood pH, apnea,. hypotension, WH, and infection
Narne of Measure Abbreviation lndicators
Neonatal Medical Index
Neonatal Morbidity Scale
Neonatal Surgical Model
National Institute of Child Health and H u m DeveIoprnent Network Model
Neonatal Intervention Scoring System
birih weight, oxygen requirements, apnea, bradycardia, ventilation requirements, Perivenîrîcular/ intraventncular hemorrhage, PDG, medication requirements, hyperbilirubinemia, major surgeries, resuscitation, meningitis, seizures, periventricular leukomalacia
Convulsions, hydocephalus, intracranial hernonhage, perinatal asphyxia, dianhea, necrotking enterocolitis, meningitis, sepsis, pneumothorax, apnea, respiratory distress syndrome, chronic Iungdisease, cardiac failure, hyperbilirubineda, hypoglycertüa, acidosis, bleeding tendency, anemia, ni1 per os, aacheostomy
Birth weight, oxygen requirement (rnax appropriate Fi02), pH, associated anomdy-
NlCHD Birihweight, small for gestational age, gender, Network race (black versus other), 1 minute Apgar (<=3). Model
Modes of respiratory support, rnedications, invasive and noninvasive monitoring, operations or procedures, feedings, use of intravascuiar catheters and administration of transfusions. Respiratory - supp 02, ECMO, surfactant, trach care, trach placrnent, CPAP, endotracheal intubation, mechanical ventilation, mech vent with musde relaxation, high-fieq vent Cardiovascular - indomethacin, vol expansion, vasopressors, pacemaker, CPR. Dmg Therapy - antiiiotic adnrin, diuretic admin, steroid admin, anti convulsant admin, amkophylline adrnin, other med, antibiotics, diuretics, treatment of metab acidosis, k+ binding resin admin- Monitoring - m u e n t vital signs, cardiorespiratoty monitoring, thermoregulated environment, noninvasive 02 monitoring, artenal pressure monitoring, urinary catheter, central venous pressure monitoring, quantitative intake and output, extensive phlebotomy (> 10 blood draws) ~etabolic/Nutrition - gavage feeding, intravenous rat emulsion, intravenous -no acid solution, phototherapy, insulin administration, potassium infirsion Transfiision - intravenous gamma globulin, red blood ceIl transfbsion (Qr =1 SmVkg), @al volume exchange transfusion, red blood ceIl transfiision (>lSml/kg), platelet transhsion, white blood ceIl transfiision, double volume exchange transfusion Procedural - transport of patient, single chest tube in place, minor operation, multiple chest
Name of Measure Abbreviation Indicators
NTiSS Cont'd tubes in place, thoracentesis, major operation, pericardiocentesis, pericardial tube in place, dialysis Vascular Access - penpheral intravenous Iine, arterial line, central venous line
Organ System Failure
Pediatn'c Risk of Mortality Score
Physiologic Stability Index
Sinkin Score
Score for Neonatal Acute Physiology
Score for Neonatal Acute PhysioIogy II
Score for Neonatal Acutc Physiology PerinataI Extension
Score for Neonatal Acute Physiology Vital Signs
Therapeutic Intervention Scoring System
OSF
PSI
SNAP
Cardiovascular System - BP, HR, Anest, Semm pH, Inotropic infiision Respiratory Systern - RR, PaC02, Pa02, Mechanical Ventilation, Pa02/Fi02 Neurologic Systern - Glascow Coma Scale, PupiIs Hematologic System - Hgb, WBC, Platlets Rend System - BüN, Creatinine, Diaiysis Organ system failure for one system defined by meeting one or more critena for a given system
Systolic BP, Diastolic BP, HR, RR, PaOUFi02, PaC02, Glasgow Coma ScaIe, pupillary reactions, PT/P7T, total bili~bin, K, Ca, Glucose, Bicarb
Cardiovascular- mean BP,HR Respiratory-RR, Pa02, Pa02/Fi02, PaC02 Neurologic - seizures, pupils Hematologic - WBC, Plat, PT andlor P m , FSP Rend - B W , Creat, UO GAST/ALT, Albumin Etabolic - Na, K, Ca, Glucose, Osmolality, pH, Bicarb(HC03)
@ 12 hours-Birth weight, gestational age, 5 minute Apgar, Peak inspiratory pressure (PiP) @ 10 days-Bi& weight, gestational age, peak inspiratory pressure (PIP), mean arterial pressure (MAPI
BP, HR, RR, Temp, P02, P02iFi02 ratio, PC02, Oxygen Index, Hct, WBC, Immature total ratio, absolute neutrophil count, plt, BUN, Creat, UO, indirect bili, direct bili, Na, K, Ca, ionized Ca, BS, pH, Bicarb, Apnea, seizures, stwl guaiac
SNAP II Birth weight, Gestational age, 5 Apgar, seven physiological variables
SNAP-PE Birth weight, small for gestational age, 5 min Apgar in addition to SNAP variables
SNAP VS Respiratory rate, hem rate, temperature, b l d pressure, signs of seizure or apnea
TISS Same as NnSS
Composite Measures of Severity Of Illness
Leading Mesures Other Measures Types o f Indicators Grouped by Factors
CRIB P b ,
NTISS T
PSI Ph ys
SNAP PhYs
SNAP FE Phys, MD, Behav (Apgar)
SNAP fl Phys, MID, Behav (Apgar)
VS SNAP Ph F
TISS T
A P W Phys, Behav
CCS
DRG
PM DRG
Medis
NBRS
NMC
NMS
NSM
NICHD
OSF
PRiSM
Sinkin Score
MID, Comp, T
MID, Comp, T
Phys
Phys, Comp, T
Phys, Comp, T
Phys, Comp, T
PhF, MID, T
Phys, MID, Behav
Phys, T
Key M/D - maturationaVdevelopmental indicators T - therapeutic interventions
- examples, BW, GA and congenital anomalies - examples, mechanical ventilation, Behav - behaviour treatment, medications
- examples, cry characteristics, state Comp -cornplication Phys - physiological, - examples, h e m rate, laboratory tests - examples, infection, seinire
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