A number of theoretical fatigue frameworks haveeen developed by nurse scientists with the intentionf guiding research, practice, and education in fa-igue. However, there is a significant gap betweenheory development and research utilization of fa-igue frameworks in clinical and intervention trials.he purpose of this report is to assess an example ofn inductive fatigue framework and a deductiveymptom management model: The Integrated Fa-igue Model (IFM) and the revised University ofalifornia, San Francisco, Symptom Managementodel (UCSF-SMM), to investigate their potential to
uide future nursing research projects on fatigue.he IFM is a fatigue-specific comprehensive frame-ork of 14 biological and psychosocial patterns that
nfluence signs and symptoms of fatigue and triggerix fatigue dimensions. The developers emphasizedhat patterns could be interrelated and influence theimensionality of fatigue. The UCSF-SMM is a mul-idimensional symptom management model embed-ed within the three nursing domains: person, envi-onment, and health and illness. The model placesymptom perceptions, symptom management strate-ies, and outcomes within these nursing domains toe the key components of a highly complex symptomanagement process. The IFM is an important de-
elopment in the understanding and conceptualiza-ion of fatigue in cancer and in HIV/AIDS. However,t does not reach the level of integration of theCSF-SMM in taking fatigue research a significant
tep forward by integrating symptom impact, symp-om management, and symptom outcomes. Both mod-
ls have significant weaknesses because of theiromplexity.
ey words: HIV, fatigue, theories, research,ractice, nursing
nfection with HIV-1 can ultimately lead to HIVisease and AIDS accompanied by a multitude ofigns and symptoms. People with HIV/AIDS reportatigue to be one of the most frequent and distressingymptoms (Barroso, Carlson & Meynell, 2003; Bre-tbart, McDonald, Rosenfeld, Monkman, & Passik,998; Breitbart, Rosenfeld, Kaim, & Funesti-Esch001; Lee, Portillo, & Miramontes, 2001;Rabkin,cElhiney, Rabkin, & Ferrando, 2004; Vogl et al.,
999). Fatigue is discussed as a primary indicator foralfunctions of endocrine organs, muscles, and the
rain (Dalakas, Mock & Hawkins, 1998; Noakes, St.lair Gibson, & Lambert, 2004; Payne, 2004; Swain,000). Fatigue has been correlated with decreaseduality of life, decreased functional status, and lowerevels of adherence to highly active antiretroviralreatments (Crystal, Fleishman, Hays, Shapiro, &ozzette, 2000; Duran et al., 2001; Henry, Holzemer,eaver, & Stotts, 1999; Trotta et al, 2003). Most
oachim G. Voss, PhD, RN, is a K-22 Research Fellow athe National Institute for Neurological Diseases andtroke, the National Institutes of Health, in Bethesda, MD.arylin Dodd, PhD, RN, is at the Department of Physio-
ogical Nursing and Carmen Portillo, PhD, RN, and Wil-iam Holzemer, PhD, RN, are at the Department of Com-unity and Health Systems at the University of California,an Francisco.
No. 1, January/February 2006, 37-50
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38 JANAC Vol. 17, No. 1, January/February 2006
escriptive studies aim directly or indirectly at un-erstanding the relationships between fatigue and itsorrelates. Only a small number of intervention stud-es focus on the improvement of fatigue in HIVBreitbart et al., 2001; Gifford, Laurent, Gonzales,hesney, & Lorig, 1998; Rabkin et al., 2004; Rabkin,agner, McElhiney, Rabkin & Lin, 2004; Wagner &
abkin, 2000). Although there are a number of the-retical frameworks available, none of these theoriesave been used to guide intervention research foratigue in HIV/AIDS. Are they too complicated orossibly too simplistic? Do they leave interventionutside their theoretical approach? Or is fatigue justoo complex and multicausal to be explained withinne framework?
To answer these questions, this report reviews twoxamples of theoretical frameworks (inductively andeductively derived) for fatigue and symptom man-gement. A brief introduction into the discourse ofheory-driven versus observational-driven theory de-elopment will help to clarify the major fundamentalifferences between the two exemplar theoreticalodels. Both models are reviewed and critiqued, and
he results from the review provide suggestions as toow theories could help guide future clinical andnterventional research to minimize fatigue. Theomplexity of HIV/AIDS in terms of diagnosis andreatment has stretched the boundaries of many dis-iplines including fatigue research. Besides nursingesearch-based fatigue models, a number of basiccience models have been developed (neuroimmu-ology, neuroendocrine-based fatigue models, andircadian rhythm models). These will not be furtheriscussed in this report because of its focus on nurs-ng research; however, for an excellent review seeayne (2004) and Swain (2000).
Perspectives on Theory and Research
Ellis (1968) defined theory as “a coherent set ofypothetical, conceptual, and pragmatic principlesorming a general frame of reference for a field ofnquiry” (p.217). Chinn and Cramer (1991) appliedllis’s definition to their interpretation of research,
heory, and practice. They stated that there is a re-iprocal relationship between practice problems
uiding theory development, theory development o
riggering new research questions, and research re-ults potentially leading to the development of betterheories.
In fatigue research, this would mean that we havesufficient knowledge base of qualitative and quan-
itative studies that contribute to a general under-tanding of fatigue. This knowledge base would ineverse then contribute to fueling new research ques-ions and theory developments and trigger outcomes-riented research to prove the effectiveness of theheoretical assumptions.
Currently, most of the fatigue research in HIV/IDS is deductive (general to specific). It is based on
xisting background literature and models from theancer field that have been applied to develop theo-etical frameworks. Less often, theoretical frame-orks are built upon inductive observations fromractice or research observations (specific to gen-ral). Independent of how the researchers came toheir theoretical assumptions, the emerging conceptsre the final building blocks of all fatigue theories.ssuming that these concepts and relationships are
inked, they can be tested empirically. After empiri-al testing has proven significance between the con-epts, investigators can apply this knowledge to eval-ate the current theory, treatment development, andutcomes research. Along this process, Meleis1997) proposed certain questions: “What specificheory propositions did the research consider? Werehese central or peripheral propositions? Did researchesults contribute to the modification of an existingheoretical framework and broaden or limit its scope?inally, did a theoretical framework provide validityf concepts or relationships to the research under-aken? Were explicit theory assumptions consideredn designing methodology?” (p. 265).
This new information is assumed to be used inheory, research, and/or practice where it can bepplied. However, in nursing research, the relation-hip between theory, research, and practice has tra-itionally been difficult and independent of theirenefits to each other. Research results transferrednto practice are associated with change of routinesnd habits and that which is most often inconvenientnd causes resistance (Higginson, 2004; Roe et al.,004).
The fatigue models that are based on inductive
bservations focus on the observation of a particular
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henomenon; for example, an intervention thatroved to be successful to decrease the perception ofatigue. These inductive observations are then theasis for the development of the theoretical model,uture research questions, and concurrent interven-ions. An example of inductive research is a commu-ity-based sample of healthy women who were foundo have internal demands that were more predictivef fatigue than their external social and role demandsLee, Lentz, Taylor, Mitchell & Woods, 1994). Win-ingham et al. found consistently across groups ofomen with breast cancer that their fatigue ratingsecreased over time when they participated in an exer-ise intervention (Winningham, 1991b; Winningham &acVicar, 1988; Winningham, MacVicar, Bondoc,nderson, & Minton, 1989). The investigators de-
igned a theoretical framework from their results touide further research into the severity and distress ofatigue, to investigate the effectiveness of exercise asn intervention for fatigue, and to reject current med-cal paradigms that rest while on cancer treatments iseneficial for fatigue. Evidence from the past decadeupports positive outcomes of theory-based exercisenterventions (Piper, Lindsey, & Dodd, 1987;chwartz, 2000;Winningham, 1991a, 1991b, Win-ingham & Barton-Burke, 2000). The experiences ofhese investigators were suggestive to apply the the-ry base on fatigue and exercise to an HIV popula-ion. Around 25 trials have been conducted witherobic and resistance exercise interventions, andesults were mixed. (For a review see Ciccolo,owers, & Bartholomew, 2004; and Dudgeon, Phil-ips, Bopp & Hand, 2004.) Although some trialshowed improvement, others showed an increase inatigue. Obviously, the perception of “fatigue is fa-igue is fatigue” is incorrect, and what was a success-ul intervention in one population might be harmfuln another.
However, even when theories have not reached theevel of sophistication we would like them to have, ineneral, they can be guidelines for researchers andlinicians in developing new ways of investigatingnd understanding fatigue in HIV/AIDS. In fatigueesearch, many facts continue to be unknown, andngoing research needs to continue to elucidate aetter understanding of the concepts. Two currentheory models as described later have been partially
ested in a small number of studies, which could be p
ndicators that fatigue in HIV has a theoretical com-lexity that is not easy to grasp. The challenge is noto look only for causal relationships between a symp-om and its treatment but to focus simultaneously onhe influences of cultural backgrounds, differentealth beliefs, or the contribution of the mind-bodyonnection in the management of a specificymptom.
In summary, the complexity of the symptomatol-gy of fatigue in HIV disease and the development of
research-based theoretical framework would beeneficial to guide future fatigue research. Other-ise, we would lack scientific proof of the methodsf to assess fatigue or in the types of interventionsesulting in inconsistent study outcomes. Analysisnd critique of the theoretical frameworks wouldequire continuous examination to integrate new re-ults and adjust them for use in HIV/AIDS patientsuffering from or at risk of fatigue.
Brief Review and Critique of CurrentFatigue Theories
Although it seems appropriate, this report does notttempt to review all of the existing fatigue modelsBarroso, 1999); however, some of the best knownodels are mentioned briefly. For an excellent re-
iew see Aaronson et al. (1999) and Payne (2004).he conceptualization of energy and fatigue has trig-ered a number of fatigue theories such as Aistairs’rganizing framework (1987), Irvine, Vincent, Gray-on, Bubela, and Thompson’s energy analysis model1994), Piper et al.’s integrated fatigue model (1987),ee et al.’s fatigue and women’s health model
1994), and Winningham’s psychobiological entropyodel (1996). Ream and Richardson (1999) summa-
ize these models as being practice-oriented and ratedhe theories to be limited in their predictive capacityOstrop, Hallett, & Gill, 2000; Tsevat et al., 1996),ut they would offer tentative guidelines for clinicalractice and directions for research (Ream & Rich-rdson, 1999). Despite criticism by Ream and Rich-rdson (1999), Piper’s integrated fatigue modelIFM) offers a theoretical framework and a validatedeasurement tool that has been developed for use in
reast cancer patients and applied to various patient
opulations (cancer, end-stage renal disease, HIV/
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40 JANAC Vol. 17, No. 1, January/February 2006
IDS, postpolio syndrome), which increases its cred-bility to be used as a framework for fatigue researchcross a broad spectrum of diseases Breitbart et al.,001; Cho & Tsay, 2004; Phillips, et al., 2004;trohschein et al., 2003; Trask, Paterson, Esper, PauRedman, 2004). The following section will review
ne of the more frequently cited theories on fatigue,he IFM, and a much broader theory on symptomanagement, the University of California, San Fran-
isco Symptom Management Model (UCSF-SMM)or their applicability to a better understanding ofatigue in HIV.
The Integrated Fatigue Model
A team of nurse scientists led by Barbara Pipereveloped the IFM in the 1980s deductively from aeview of the literature on cancer fatigue (Piper,993; Piper et al., 1987). It is a comprehensiveramework that describes 14 biological and psycho-ocial patterns that influence signs and symptoms ofatigue in clinical populations, specifically womenith breast cancer. The developers understood theide range of contributing factors to be interrelated
o each other, which leads to chronic fatigue experi-nces for cancer patients. In addition, the IFM indi-ectly gives multiple possibilities on how fatigue cane manifested and provides a base for the assessmentf nursing practice. The IFM is currently the onlyodel proposed for guiding fatigue research in HIV/IDS and in the investigation of the multiple con-
ributing factors. The model is based on the definitionhat fatigue in HIV/AIDS is a perception of unusualr abnormal whole-body tiredness disproportionateo or unrelated to activity or exertion. Fatigue cannote resolved with sufficient sleep or rest. It is termedcute when experienced for less than a month andhronic when experienced for more than one monthPiper, 1993).
According to Piper (1998), fatigue in HIV/AIDS isxperienced on six dimensions: temporal (circadianifferences), sensory (intensity and local or systemicymptoms of fatigue), cognitive/mental (alteration inemory, concentration, attention, and alertness), af-
ective/emotional (increasing irritability, impatience,ack of motivation, depression), behavioral (impact
n activities of daily living), and physiological a
changes in laboratory, radiographic, and physicalxams). One or more patterns (recurring characteris-ics over time for a specific individual) can influenceach fatigue dimension. There are 14 types of pat-erns and 6 fatigue dimensions depicted in Figure 1.he figure lists the unidirectional factors that influ-nce the experiences of fatigue in cancer and inIV/AIDS (Piper, 1993, 1998) posited to contribute
o fatigue in HIV. The following paragraph describesxamples of theoretically derived relationships asroposed in the IFM model.
The prevalence of anemia in HIV ranges from0% to 90% (Wilson & Cleary, 1996). In addition,he complications of HIV-related lung disease (Mur-ay, 1996; Rosen, 1996; Schneider & Rosen, 1997)upport the relationship to oxygenation patterns. Anncrease in lactate dehydrogenase, for example, inneumocystis carinii (Darko, McCutchan, Kripke,illin, & Golshan, 1992) supports the theoretical
elationship between the accumulation of toxic me-abolites and fatigue. Progressive wasting, weightoss, and altered nutrition (Parisien, Gelinas, & Co-ette, 1993), elevated total globulin levels (total pro-ein minus albumin) (Darko et al., 1992), and in-reased resting energy metabolism support theheoretical link between fatigue and energy sub-trates. Empirical results regarding decreased motorunctioning (Perkins et al., 1995) and decreased func-ional status (O’Dell, Hubert, Lubeck & O’Driscroll,996) support the theoretical relationship betweenatigue and activity/rest patterns. Insomnia and sleepatterns (Darko et al., 1992; Lee, Portillo, &iramontes, 1999, 2001) support the theoretical re-
ationship between fatigue and altered sleep/wakeatterns.
Results showing an association between lowerD4� cell counts and increased fatigue levels
Darko et al., 1992; Lee et al., 1999, 2001) supporthe theoretical relationship between fatigue and dis-ase severity. Zidovudine-induced anemia (Fischl,989; Fischl et al., 1989) and mitochondrial toxicityDarko et al., 1992) support the relation to treatmenttrategies. Pain, diarrhea, and night sweats estab-ished the relationship between increased number andistress of symptoms and symptom patterns (Lubeck
Fries, 1993; Wilson & Cleary, 1995).The IFM model posits that psychological patterns
re linked to fatigue. Anxiety, depression, lack of
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otivation, and metal health problems (O’Dell,eighen, & Riggs, 1996; Perkins et al., 1995;ilson & Cleary, 1995) are common in HIV and
re associated with fatigue. Adrenal insufficiencyKaplan et al., 1987); elevation of humoral mediatorsuch as interferon, tumor necrosis factor, interleukinsPiper, 1993); and electrolyte imbalances (Yu-Ya-iro, 1994) provide evidence for a relationship withetabolic regulation and transmission. Environmen-
al factors such as exposure to noise, heat, allergens,nd altitude (Piper, 1993) and social factors such asultural and ethnic practices (Piper, 1993), sexualreferences, and drug abuse patterns (Palenicek etl., 1993) support the relationship to environmentalatterns. Significant life events are posited to bessociated with fatigue, and the documented changesn the lives of people with HIV/AIDS such as loss of
job, relocation to a new city, loss of friends, and
igure 1. The Integrated Fatigue Model. Modified with perm. B. Williams (Eds.), HIV nursing and symptom managemen
rief support the relationship to social patternsPiper, 1993). Finally, differences in innate host fac-ors such as age, gender (Semple et al., 1993), race,nd genetic makeup (Piper, 1993) would support thennate host patterns.
Many of these original references seem to be out-ated; however, a large number of the relationshipsiper proposed have been confirmed by multiple
nvestigators. Therefore, Piper has significantly con-ributed to the discourse and the theoretical develop-ent of fatigue in HIV/AIDS. Yet Piper has been
riticized for not testing these proposed relationshipsn an HIV population. Some of the proposed factorseflect the knowledge of the early to mid 90s andave not been currently updated. Finally in 2004,hillips et al. based their study on Piper’s framework
o test associations of physiological, psychological,nd sociological factors with fatigue in a sample of
from Piper, B. F. (1998). Fatigue. In M. E. Ropka, &ton: Jones and Bartlett, p. 451.
ission
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42 JANAC Vol. 17, No. 1, January/February 2006
en and women with HIV/AIDS (N � 79). Theyound significant relationships between fatigue andleep quality, daytime sleepiness, HIV-related symp-oms, state anxiety, trait anxiety, depression, anderceived stress.
One criticism of the model is that the 14 factorsnfluence to some degree the fatigue experiences ofeople with HIV, but they are not organized into aystem by the distress they cause or by any hierarchy.he IFM allows selection of certain patterns and
nvestigation of one or multiple relationships be-ween the patterns and the symptom dimensions.ach pattern and its relationship with the fatigueimensions generates a multitude of potential causalypotheses.
The IFM fails, however, to indicate which of theatterns are interrelated, whether there is a reciprocalelationship between causal patterns and certain fa-igue dimensions, and if the patterns can be weightedr hierarchically ordered (Winningham et al., 1994,inningham & Barton-Burke, 2000). Therefore, the
FM generates unidirectional and testable hypothesesut provides limited guidance for strategies to reducer manage fatigue because interventions and out-omes are not integrated into the IFM.
The Revised Symptom Management Model
The UCSF-SMM is not a fatigue-specific modelut is more a multidimensional symptom manage-ent model that is embedded within three nursing
omains: person, environment, and health and illnessDodd et al., 2001, Larson et al., 1994). The systemas developed by a number of scholars at the Uni-ersity of California, San Francisco, School of Nurs-ng, Center for Symptom Management and is theesult of ongoing research on the model. The UCSF-MM consists of three inner circles with spheres
nteracting between symptom experience and symp-om management strategies (process), and the thirdircle with its potential outcomes to consider in ad-ition to a change in the severity, frequency, oruration of the symptom. This interdependent pro-ess of symptom management is placed within threeomains of nursing that interact with each other (seeigure 2). The person dimension represents all of the
ndividual variables that influence symptom manage-
ent the environment represents all of the social andultural variables, and finally, health and illness rep-esents the risk factors for the symptom such asnjury or infection.
The model is based on the following six assump-ions:
Gold standard is the self-reported symptom expe-rience of the patient.Presence of a symptom is not required for theapplicability of the model. The risk for develop-ing a symptom is a reason for the initiation ofinterventions before individual symptoms can beexperienced.Nonverbal patients experience symptoms, andsymptom interpretation by family members andcaregivers is assumed to be accurate for symptommanagement.Management strategies can be targeted towardthe individual, groups, a family, or the workenvironment.Symptom management is a dynamic process that ismodified by individual outcomes and environmen-tal influences.
odel Components
Person domain. The person’s views and re-ponses to the symptom experience uniquely defineemographic, physiological, psychological, and so-iological person-variables. Developmental variablesncompass the level of maturity of an individual.epending on the focus, symptom, or population of
nterest, the person-variables can be limited or ex-anded. Lee and Taylor (1996) documented inidlife women that fatigue has an impact on the
evelopmental stage, when menopausal symptomsffect the quality of sleep. Rankin demonstrated inwo studies (1990, 1992) that gender affected cardio-ascular outcomes in women with coronary arteryypass graft surgery and that women after myocar-ial infarction experienced higher morbidity andortality.
Health/illness domain. Health and illness vari-bles are unique to the states of health and illness ofn individual and include risk factors, injuries, and
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isabilities. Janson and Carrieri (1986) found thatifferent types of pulmonary diseases produceduantitatively and qualitatively different symptomxperiences (Janson, Covington, Fahy, Gold, &oushey, 1999). The type and extent of cancer de-
ermined treatment choices (Facione, Misakowski,ood & Paul, 2002), and in terms of received treat-ent affected risk factors for related morbidities
Dodd et al., 1999).
Environment domain. Symptoms occur in a spe-ific environment and include physical, social, andultural variables. The home, work, or hospital is anxample of physical environment in which socialetworks and interpersonal relationships are part ofhe social environment. Cultural aspects of an envi-onment are beliefs, values, and practices defined inart by one’s ethnic, racial, or religious group. Hum-hreys, Lee, Neylan, and Marmar (1999) and Hum-hreys (2003) reported that being temporarily shel-
igure 2. The Revised University of California, San Franciscrom Dodd, M., Janson, S., Facione, N., Faucett, J., Froehlicymptom management. Journal of Advanced Nursing, 33(5),
ered because of domestic violence had a significantmpact on women’s perceptions regarding fatiguend sleep. Asthma patients who were taught self-anagement in individual sessions had better adher-
nce to therapy and improved medication skills thanhose taught in groups (Janson et al., 1999, 2003).hese three nursing domains of person-environment-ealth/illness underlie the entire model, whereas theymptom experience, symptom management strate-ies, and outcomes are the central elements of theodel.
Symptom experience. Symptom experience cane divided into symptom perception by the individ-al, evaluation of the meaning of the symptom, andeaction or response to the symptom. The perceptionf fatigue, for example, depends upon one’s state oflertness but also on the judgment of everyday per-eptions and feelings. The symptom is evaluated byudging the severity, cause, treatment options, and
ptom Management Model. Reprinted with permission. S., Humphreys, J., et al. (2001). Advancing the science of7.
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ffects on quality of life or daytime functioning.esponses to fatigue can be multidimensional and
Symptom management strategies. Symptomanagement is necessary to prevent or manage neg-
tive health outcomes through professional and self-are strategies. Identifying the focus for interventionsollows assessment of fatigue. Interventions targetne or multiple symptoms and try to achieve theesired outcome. This process is dynamic and re-uires frequent changes in strategies because of re-ponse or lack of acceptance and adherence. Thesetrategies are defined by the questions on what,hen, where, why, how much, to whom, and how
hese interventions will be delivered.
Symptom outcomes. Desired outcomes simulta-eously emerge from management strategies androm the symptom experience. In addition to im-rovement of symptom status, evaluation of out-omes needs to be considered and measured, such asunctional status, emotional status, mortality, mor-idity/comorbidity, quality of life, and costs. Theseroader based outcomes factors need to be under-tood in relation to each other as well as to theymptom status or pattern.
The application of the current knowledge on fa-igue in HIV into the UCSF-SMM offers systematicnderstanding of current research results, and it of-ers directions for future research. In the person do-ain, individual (person) variables may influence the
evel of fatigue in HIV/AIDS patients including ageSingh, Squier, Sivek, Wagener, & Yu, 1997), gen-er, ethnicity (Voss, 2005), income, educationalackground, coping styles, and so on. In our studyith HIV/AIDS outpatients in Texas (N � 372), we
ound that educational background was an indepen-ent predictor of physical health and fatigue (Voss,005). The interaction between the person domainnd the health and illness domain is the location tontegrate the complex interplay of stress-psychoneu-oimmunology and HIV (Antoni, 2003). The healthnd illness domain includes the symptom burden ofhe HIV disease itself and risk factors such as addic-
ion, presence of opportunistic infections, possible v
ide effects of treatments, and present or developingomorbidities. The environment domain encom-asses the work, home, and hospital influences; thempact of social networks; and culture-specific be-iefs, values and practices associated with fatigue.he symptom experience circle includes measure-ent issues of fatigue in HIV (Aaronson, et al.,
999), as well as other associated symptoms of fa-igue such as pain, insomnia, and depression. Theymptom management circle encompasses interven-ions such as testosterone supplementation, physicalxercise, and psychostimulants that have been inves-igated to decrease fatigue. The outcome circle in-ludes the concepts that provide opportunities tovaluate the effectiveness of interventions for theatients as well as for society.
Each circle provides a unique opportunity for theext generation of research questions to be asked. Inhe person circle, one could hypothesize that age is aontributing factor that increases fatigue in peopleith HIV/AIDS secondary to a hormonal imbalance
aused by HIV-induced damage in the hormone pro-ucing glands and the brain. Other areas of interestould be the following:
1. Where is fatigue perceived (brain or muscle)?2. How is fatigue perceived (chemical imbalances
or psychological perception)?3. What role do cytokines play in the fatigue
perception?4. How is HIV-related fatigue different from fa-
tigue perceived after a marathon (mitochon-drial intoxication or exertion)?
5. How do patients adjust to various fatiguelevels?
6. Are fatigue levels comparable between groups,ages, or genders?
There are open questions in the health and illnessomain: Which risk factors actually contribute toigher levels of fatigue? What are health behaviorshat prevent fatigue? While progress has been maden the measurement of perception of fatigue, little isnown about how symptoms are evaluated by thendividual. The same is true for the responses toymptoms. Does severity, duration, or quality of fa-igue influence the evaluation or response to inter-
entions? Thus far, these areas are insufficiently ex-
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lored. Interventions relevant to fatigue receivedncreasing interest in the last couple of years and wille an important field of research. Results will impactlinical practice of healthcare providers. The effec-iveness of self-care strategies across populations andhe costs of fatigue caused by disability are a few ofhe unknown issues reflected in the symptom out-ome circle. Little is known about how fatigue andargeted interventions influence mortality and mor-idity or how an intervention can enhance long-termunctional or emotional status.
The UCSF-SMM is presently one of the mostlaborate models for symptom management. It ispplicable not only to fatigue in HIV but to allymptoms of healthy and ill people. It can be auiding framework for future research on fatigue inIV. The UCSF-SMM is still an evolving model,
nd some issues need to be investigated further; forxample, how to study simultaneously occurringymptoms or symptom clusters. Currently, the modelocuses on the patient’s primary symptoms (like fa-igue), but with symptom clusters, the symptom inhe forefront could move to the background and otherymptoms (such as depression, neuropathy, and in-omnia) become more or less severe or distressing.
Summary and Discussion
The IFM depicts linear relationships between fa-igue experiences in HIV and theoretically derivedauses. The UCSF-SMM is a multidimensional, in-eractive, process-oriented model derived from re-earch in various aspects of symptom management.he model presented by Piper et al. was an importantevelopment for the understanding and explanationf fatigue in women with cancer and was extended tother types of cancer and HIV/AIDS. Only steadyrogress on the issues of fatigue in cancer helped tohape the understanding of the complex cancer-re-ated fatigue syndrome. Piper was a pioneer in pro-iding a theoretical explanation and introducing aniversal model for fatigue in cancer, which lateras extended to HIV/AIDS. The IFM integrated
esearch results regarding HIV/AIDS that providedvidence that links key concepts in HIV disease andatigue. However, because of its linear nature, the
odel does not reach the level of guidance necessary d
o take theory development or research on fatigue inIV/AIDS a significant step forward. This is because
he model describes the phenomenon and does notrovide directions for interventions.
The UCSF-SMM evolved over the last decaderom research results by scholars at UCSF, San Fran-isco, School of Nursing, Center for Symptom Man-gement. It is a conceptual model based on the threeursing domains (person, environment, health andllness) that interact with symptom experience, man-gement, and multidimensional outcomes. In thisodel, symptom management can be focused on
ealthy or ill people, children or adults, or the care-iver, as well as on the patient, and can be applied toifferent demographic or cultural populations. Be-ause of the flexibility of the model (not disease-ocused) it can be applied to diverse clinical popula-ions or healthy individuals. The UCSF-SMM isirectional in that it begins with the symptom expe-ience of the person or their family and caregivers.hese perceptions initiate a cascade of followingctions, interactions, and results. Similar to the nurs-ng process, which includes data collection, goalefinition, intervention planning, and evaluation, theCSF-SMM has these repetitive circles of percep-
ion-management-outcomes that are complete only ifhe symptom is well-managed. The strength of thisodel is its ability to offer researchers and cliniciansclear understanding of symptoms through the feed-ack of their patients and their environment. How-ver, the multitude of influential factors in this models also one of its weaknesses. The complexity can beverwhelming for an investigator trying to decidehich variables to select for a study. Therefore, usef smaller parts of the UCSF-SMM provides anxcellent guideline for complex relationships andnterdependencies between the nursing domains andhe symptom concepts.
Virtually, the IFM could be incorporated withinhe UCSF-SMM. The fatigue dimensions of the IFM,or example, represent the symptom experience inhe health and illness domain of the UCSF-SMM.he social, life event, environmental, and innate hostatterns of the IFM represent the environment do-ain in the UCSF-SMM but do not represent the
ymptom management strategies circle. The otheratterns of the IFM can be found within the person
omain of the UCSF-SMM but do not represent the
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actors in the outcomes circle. Table 1 conceptualizeshe present knowledge about fatigue in HIV into theymptom management model and possible areas ofntervention research.
The UCSF-SMM is presently one of the leadingheories for nursing research on fatigue in HIV, be-ause it focuses not only on the individual level ofhe patient but takes contextual and health/illnesserspectives into account as well. It qualifies as aiddle-range theory because of its wide conceptual
ange and ability to generate a plethora of workingypotheses. The theory is abstract enough to extendeyond a given place, time, and population but spe-ific and sufficiently close to test and generate dis-inct questions for investigations or interventionsWalker & Avant, 1995). With its use, a multitude ofesearch possibilities evolve. This process will helpo determine whether fatigue is a symptom or a
able 1. The University of California, San Francisco Sym
Symptom Experience
erson variables:Age, gender, income,
education, ethnicity
Perception of fatigueFatigue as burden one has t
carryFatigue lets people nap
more, be less social, haveless focus and interests
ealth/ illness variables:HIV infection, hepatitis
B & C infection,opportunisticinfections,neoplasms,comorbidities,intravenous drug use,hormonal imbalance(low testosterone)
situation, culturalvalues, workplace,social support
StigmaSocial isolationLack of social supportLack of transportationLack of health careLack of finances
yndrome, and if it is a syndrome, which other symp- s
oms accompany fatigue in HIV. The answers tohese questions are found in the future research ef-orts of a number of disciplines, one of which isursing. Collaborative efforts will be necessary tonderstand the personal experience of fatigue, theomplex interplay between the immune system andhe brain, antiretroviral treatment effects in the hu-an body, and the social and political influences.
Future of Theory Development inHIV/AIDS Fatigue
J. Barroso, a fatigue researcher in HIV/AIDS, isonducting an ongoing study until 2007 to validatehe first HIV/AIDS-specific fatigue model (personalommunication, March 10, 2005). This model isased on existing fatigue research results and Barro-
arroso et al., 2002; Barroso & Lynn, 2002; Barrosot al., 2003). The model displays the anticipatedelationships among the variables to be studied (seeigure 3). The four broad areas that may influenceIV-related fatigue are personal, HIV-related, phys-
ological, and psychosocial variables. In figure 3, theariables to be measured in each of these areas arehown outside of the circle, with the gray arrowsndicating whether an increase or decrease would bexpected to increase HIV-related fatigue. For someersonal and HIV-related variables, existing researchs conflicting; these are marked with question markss unknown. Finally, sleep quality is presented be-ween physiological and psychosocial variables, be-ause poor sleep can result from factors in each ofhese areas. The trajectory at the bottom of the figureepresents the changes over time that will be ob-erved. The authors anticipate the usefulness of theefined model and look forward to the completion ofhe validation study.
igure 3. Multidimensional Model of HIV-Related Fatigue. Rrofessor, Duke University, Durham, NC.
Acknowledgment
Special thanks to Dr. Katherine Lee for herhoughtful review of this article.
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