Puin, 28 (1987) 27-38 Elsevier 27 PA1 00974 The Varni/Thompson Pediatric Pain Questionnaire. I. Chronic musculoskeletal pain in juvenile rheumatoid arthritis James W. Varni *, Karen L. Thompson * * and Virgil Hanson * * * * Behavioral Pediatrics Program, Orthopaedic Hospital, University of Southern California, Los Angeles, CA 90007 (U.S.A.), **Department of Psychology, Universily of Southern California, Los Angeles, CA 90089-106I (U.S.A.), and *** Division of Rheumatology, Children’s Hospital of Los Angeles, University of Southern California, Los Angeles, CA 90027 (U.S.A.) (Received 29 October 1985, revised received 20 May 1986, accepted 4 June 1986) Summary The Vami/Thompson pediatric pain questionnaire (PPQ) represents an attempt to empirically assess the complexities of pediatric chronic, recurrent pain. This initial investigation targeted chronic musculoskeletal pain in children with juvenile rheumatoid arthritis. The PPQ provides a developmental step toward the comprehensive assessment of the pain experience in children with chronic pain. Further reliability and validity studies are needed to determine the generalizability of the PPQ with larger numbers of children with a variety of acute and chronic pain experiences across a diversity of settings. Key words: Vami/Thompson pediatric pain questionnaire; musculoskeletal pain; juvenile rheumatoid arthritis; chronic pain Introduction Chronic pain in children remains a largely underdeveloped area of cognitive-bio- behavioral research, particularly in contrast to the extensive literature on adult chronic pain [27]. Oster [12] studied the prevalence rates of recurrent pain in children, finding musculoskeletal, cephalic, and abdominal pain to be the most common sites. A review of the literature shows that 15.5% of school-age children have recurrent musculoskeletal pain, and that 4.5% of the children have pain for longer than 3 months severe enough to cause interruption of normal activities [13]. Correspondence IO: James W. Vami, Ph.D., Behavioral Pediatrics Program, Orthopaedic Hospital, 2400 South Flower Street, Los Angeles, CA 90007, U.S.A. 0304-3959/87/$03.50 0 1987 Elsevier Science Publishers B.V. (Biomedical Division)
Transcript
Puin, 28 (1987) 27-38
Elsevier
27
PA1 00974
The Varni/Thompson Pediatric Pain Questionnaire. I. Chronic musculoskeletal pain in juvenile
rheumatoid arthritis
James W. Varni *, Karen L. Thompson * * and Virgil Hanson * * * * Behavioral Pediatrics Program, Orthopaedic Hospital, University of Southern California,
Los Angeles, CA 90007 (U.S.A.),
**Department of Psychology, Universily of Southern California, Los Angeles, CA 90089-106I (U.S.A.),
and *** Division of Rheumatology, Children’s Hospital of Los Angeles, University of Southern California, Los Angeles, CA 90027 (U.S.A.)
(Received 29 October 1985, revised received 20 May 1986, accepted 4 June 1986)
Summary The Vami/Thompson pediatric pain questionnaire (PPQ) represents an attempt to
empirically assess the complexities of pediatric chronic, recurrent pain. This initial investigation targeted
chronic musculoskeletal pain in children with juvenile rheumatoid arthritis. The PPQ provides a
developmental step toward the comprehensive assessment of the pain experience in children with chronic
pain. Further reliability and validity studies are needed to determine the generalizability of the PPQ with
larger numbers of children with a variety of acute and chronic pain experiences across a diversity of
Chronic pain in children remains a largely underdeveloped area of cognitive-bio- behavioral research, particularly in contrast to the extensive literature on adult chronic pain [27]. Oster [12] studied the prevalence rates of recurrent pain in children, finding musculoskeletal, cephalic, and abdominal pain to be the most common sites. A review of the literature shows that 15.5% of school-age children have recurrent musculoskeletal pain, and that 4.5% of the children have pain for longer than 3 months severe enough to cause interruption of normal activities [13].
Correspondence IO: James W. Vami, Ph.D., Behavioral Pediatrics Program, Orthopaedic Hospital, 2400 South Flower Street, Los Angeles, CA 90007, U.S.A.
Thus. pediatric chronic musculoskeletal pain appears to be significantly prevulcnt and disabling as to warrant independent study.
In children with chronic musculoskeletal pain, the prototype for inflammatory chronic arthropathy is juvenile rheumatoid arthritis. As the most common conncc-
tive tissue disease in children, with an estimated prevalence of all forms of pediatric
chronic arthritis as high as 250,000 American children and an estimated incidence of 1.1 cases per year per 1000 school-age children [14], juvenile rheumatoid arthritis provides an exemplary disorder for the investigation of chronic, and more specifi-
cally. musculoskeletal pain in children. The disease typically manifests itself before 16 years of age, with peak onset in the age groups 1 --3 and X---l2 years. In general. girls are affected twice as often as boys.
The term arthritis refers to objective inflammation of the connective tissues of a
joint, characterized by swelling, heat and pain [4,7]. Juvenile rheumatoid arthritis may best be conceptualized as a syndrome with 3 distinct subtypes of disease onset:
systemic, polyarticular, and pauciarticular [4,7]. Systemic onset occurs in approxi- mately 20% of the patients and is characterized by intermittent fever (daily intermit- tent temperature elevations to 103°F or more), with or without rheumatoid rash or
other organ involvement (e.g., pericarditis), and joint involvement. Polyarthritis onset occurs in 30-40% of all patients and is characterized by arthritis in 5 or more joints. Pauciarticular onset occurs in 40-50% of all patients and is characterized by arthritis in 4 or fewer joints.
Varni and Jay [25] recently reviewed the literature pertaining to pain in juvenile rheumatoid arthritis, identifying only 3 studies [2,9,19]. Two studies [9,19] attempted
to measure only pain intensity and neglected to consider the children’s cognitive-de- velopmental stage and conceptualizations of pain and illness. As cogently stated by
Melzack (111, ‘The word ‘pain’ refers to an endless variety of qualities that are
categorized under a single linguistic label, not to a specific, single sensation that
varies only in intensity. Each pain has unique qualities. To describe pain solely in terms of intensity is like specifying the visual world only in terms of light flux without regard to pattern, color, texture. and the many other dimensions of visual experience.’ Further, as pointed out by Varni [23], the term pain is an abstract concept, which may be meaningless to children in the preabstract stage of cognitive development. Thus, the children’s cognitive-developmental stage and conceptualiza-
tions of pain and illness may influence their understanding of the pain experience and consequently affect its meaning for them [21,23]. A study by Beales et al. [2)
provides some support for this hypothesis. Beales et al. [2] studied arthritic pain in children 6-17 years of age. Their results showed that all children reported some
sensation from their joints. Of the 11 sensation terms utilized, 100% of the children reported an ‘aching’ sensation. Fifty-three percent of the 12-17 year olds and 50% of the 6-11 year olds described a sharp sensation (‘cut,’ ‘pricked,’ ‘smacked,’ ‘pinched’). Fifty-three percent of the 12-17 year olds and 33% of the 6-11 year olds reported a ‘burning’ sensation in their involved joints. Thus, when words other than the term pain are used, children with juvenile rheumatoid arthritis are able to report discomfort in their joints, pointing out the importance of a developmentally appropriate assessment approach [21,23].
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The ideal assessment of pediatric pain requires an interdisciplina~, multidimen- sional and comprehensive approach, combining self-report, behavioral, cognitive, socio-environmental, medical and biological parameters [21,23]. The majority of research in pediatric pain assessment has not addressed all of these parameters; therefore, conclusions about the reliability and validity of the existing measures must be drawn cautiously.
Selection of colors to communicate pain intensity has received some attention in the literature. Red has been reported as the color most frequently chosen by children to represent pain 118,201. In an assessment of pain relating to intramuscular injections with pre~ndergarteners, Eland [5] used a self-selected color spectrum to assess pain. The children, aged 4.9-5.9 years, were asked to select a color similar to the ‘event most painful’ for them from 8 color squares. The child then selected squares to represent ‘like hurt but not quite as much as the most painful event,’ ‘like something that hurts just a little’ and ‘like no hurt at all.’ This 4-color scale was used successfully to assess the children’s procedural pain with and without a skin coolant sprayed on the injection site. In a study of recurrent migraine headaches and chronic musculoskeletal pain, children were asked to draw themselves when in pain using 8 colored markers. Red and black were most frequently selected by the children in their drawings, with no significant differences found for age or sex [22].
To assess the site of pain, Eland [6] asked 172 hospitalized 4-10 year olds to place an X on a body outline to show where they hurt. Of the 172 children, 168 correctly placed the X on the body outline co~esponding to their pathology, surgical procedure, or painful events that occurred during the course of their hospitalization. This finding suggests that children can correctly localize the site of their pain.
The visual analogue scale (VAS) has also been used to examine children’s perception of pain. Abu-Saad [l] compared ratings on a 10 cm VAS to behavioral and physiological parameters for hospitalized children. There was no correlation between the child’s physiological measures (pulse, respiration, blood pressure) and responses on the VAS. There was a significant relationship between the child’s ratings on the VAS and body, facial, and vocal manifestations of pain. While the study sample was small and age-restricted (10 9-16 year olds) and did not assess reliability, the measure of association does provide some support for the validity of the 10 cm VAS as an indicator of postoperative pain with children old enough to comprehend the use of an analogue scale anchored by the words ‘no pain’ and ‘ very severe pain.’ Scott et al. [19f measured arthritic pain in children and adolescents, ages 2-17 years, with a VAS, finding that 11% of the children, mostly below age 5, were unable to complete the VAS. Beales et al. [21 found that all children and adolescents between 6 and 17 years of age were able to complete a VAS for assessing arthritic pain intensity.
Faces scales have also been used to assess pain in younger children. LeBaron and Zelzer [lo] utilized a 5-point Likert scale presented together with faces showing increasing degrees of distress for children less than 10 years of age undergoing bone marrow aspirations during the treatment of childhood cancer. The children’s seff-re- port of procedural pain on the faces scale sig~fic~tly correlated with independent
observers’ recordings of behavioral manifestations of procedural pain and ohservcr\’
ratings of procedural pain on the same 5-point Likert scale. Savedra et al. [IS] assessed children’s selection of pain descriptors. presenting a
list of 24 words to a sample of 100 hospitalized children and 114 school children
between 9 and 12 years of age. Most children (85%) selected between 3 and 13 words. Based on Melzack [ll], 16 were sensory words, 4 were affective words. and 4
were evaluative words. The children also generated additional pain descriptors not listed to describe their worst pain experiences, such as throbbing, burning, piercing,
and bad, consistent with the Ross and Ross (171 study indicating that children can generate pain descriptors in describing their pain experiences. Taken together. these
findings suggest that pain descriptors may provide information beyond pain inten-
sity in describing the pain experience in children. For adult chronic pain patients, the most widely used and respected assessment
instrument has been Melzack’s McGill Pain Questionnaire (MPQ) [ll]. Subsequent
to its publication, other investigators have further developed the reliability and validity of the MPQ across a diversity of adult pain syndromes, including arthritic pain [3], low back pain [15], chronic pelvic pain [16], and cancer pain [S]. Recently, Varni and Thompson (281 developed the Varni/Thompson Pediatric Pain Question- naire (PPQ), modeled after the MPQ but designed to be sensitive to the cognitive-
developmental conceptualizations of children, with child, adolescent, and parent
forms. The PPQ-Child Form addresses the intensity of pain, the sensory, affective, and evaluative qualities of pain, and the location of pain in a form comprehensible
to children. The PPQ-Parent Form consists of,components similar to the PPQ-Child Form to allow for cross-validation of the child’s reporting of pain. A comprehensive family history section addresses the child’s pain history and family pain history.
with questions pertaining to symptomatology, past and present treatments for pain, and socio-environmental situations which may influence pain perception and report. The present study reports the first data-based utilization of the PPQ, targeting chronic musculoskeletal pain in children with juvenile rheumatoid arthritis for this
initial investigation.
Methods
Subjects The subjects were selected from the clinic population of children with juvenile
rheumatoid arthritis receiving treatment in the Division of Rheumatology at the Children’s Hospital of Los Angeles. Candidates for study participation were re- quired to be between the ages of 4 and 16 years and were identified for the study by systematic reviews of the rheumatology clinic schedules. The diagnosis of juvenile rheumatoid arthritis was confirmed by a pediatric rheumatologist for each child participating in the study.
Twenty-five children, 19 females (76%) and 6 males (24%). comprised the study sample. Twenty-two percent of the subjects had pauciarticular onset, 48% had polyarticular onset, and 26% had systemic onset juvenile rheumatoid arthritis. One
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subject had unspecified rheumatological disorder. Ninety-one percent of the children were on disease modifying medication. The mean age of the children was 9.5 years, with a range of 5.0-15.2 years (S.D. = 3.17). The ethnic composition of the group was 57% Caucasian, 22% Hispanic, 17% Black, and 4% Asian. Sixty-five percent of the families reported their religion as protestant and 35% of the families reported their religion as catholic. Eighty-three percent of the mothers responding to the questionnaires were married, 9% were divorced, 4% separated and 4% single. The average annual family income was between 10,001 and 30,000 dollars (52% of the sample). Twenty-two percent of the sample had an average yearly income of between 30,001 and 50,000 dollars. Seventeen percent of the families chose not to respond to the question regarding annual income.
Procedure The mothers of the children identified as possible study candidates were ap-
proached at the time of a scheduled rheumatology clinic appointment and invited to participate in the study. Written informed consent was obtained at this time from the mothers. Two parents failed to complete all of the assessment forms. The psychological and medical assessments were all conducted in the outpatient clinic examining rooms or the Rehabilitation Unit at Children’s Hospital of Los Angeles.
Instruments Vami/ Thompson Pediatric Pain Questionnaire (PPQ) *. The PPQ was adminis-
tered within a structured interview format to provide an assessment of the children’s and parents’ perceptions of the child’s pain experience. The child and parent were interviewed individually by KLT prior to the child’s physical examination by the pediatric rheumatologist. The interviewer was available at all times to answer any questions that the child and parent had regarding any aspect of the PPQ.
Present pain and worst pain intensity for the previous week were assessed by a visual analogue scale (VAS). Each VAS is a 10 cm horizontal line with no numbers, marks, or descriptive vocabulary words along the length of the line. The child VAS is anchored with developmentally appropriate pain descriptors and happy and sad faces. The adult VAS is anchored by the phrases ‘no pain’ and ‘severe pain.’ All pain ratings were made separately by the child, mother, and pediatric rheumatolo- gist. The subjects had no knowledge of how each other responded to the scale. The child, mother and physician rated present pain. The child and mother rated the worst pain for the previous week. The physician rated present pain intensity immediately after conducting the rheumatology physical examination.
A color-coded pain rating scale also measured pain intensity. Four developmen- tally appropriate categories of pain descriptors were provided along with 8 standard crayons and a body outline. The child was instructed to color in the 4 boxes underneath each descriptive category representing pain intensity, and then to color in the body outline with the selected color/intensity match.
* The PPQ is available upon request from Dr. Varni.
In order to assess the sensory, affective and evaluative qualities of the child’s pain experience, a list of pain descriptors was provided. with the child instructed to circle
the words which most appropriately described his/her pain. Finally. on the PPQ Parent Form, a number of socio-environmental and family and child background
information were elicited. Disease activity index. The Disease Activity Index was designed to provide a
global assessment of disease activity as determined by the pediatric rheumatologist. The categories included severe, moderate, mild, quiescent (no physical or laboratory
signs, on medication), and remission (quiescent for 2 months without medication). The pediatric rheumatologist completed this rating at the conclusion of the physical
examination of the child.
Visual analogue scale Table I presents the correlation coefficients between the child, parent, and
physician ratings on the VAS. VAS pain intensity scores were based on line length
to the nearest 0.5 cm. All correlations were highly significant for present pain (P < 0.001) and worst pain (P -C 0.013). Table II shows the child’s, parent’s and physician’s ratings on the VAS for present pain and the child’s and parent’s ratings
for worst pain during the preceding week. Paired t tests between child/parent (t = - 2X9, child/physician (r = - 1.43) and parent/physician (r = 1.88) showed
TABLE I
CORRELATIONS BETWEEN PAIN INTENSITY RATINGS ON THE VAS
Present pain
Parent Physician
Worst pain
Parent
Child 0.12 * 0.65 * 0.54 **
Parent 0.85 *
* P -c 0.001.
** P i 0.013.
TABLE II
PRESENT AND WORST PAIN INTENSITY ON THE VAS
Mean
S.D.
Range
Present pain Worst pain
Child Parent Physician Child PaXIll
1.63 2.93 2.38 4.74 4.21 2.12 2.85 2.64 3.91 3.18
O-8 O-10 O-8.5 O-10 0.5-10
PAIN INTENSITY
Remlsslon Quiescent Mild Moderate Severe
Dl5EASE ACTIVITY
Fig. 1. The relationship between pain intensity ratings on the visual analogue scale and the disease
activity index.
no significant differences in present pain intensity ratings. The alpha level was set at 0.05 for a two-tailed test and adjusted using the Bonferroni inequality to control the experimentwise type I error rate [29]. No difference was found in a comparison of child/parent worst pain intensity ratings (t = 0.56). Fig. 1 indicates that as physi- cian-rated disease activity increased, there was a corresponding increase in rated present pain intensity by the child, parent, and physician.
Color-coded pain rating scale Table III represents the selection of colors by the children on the body outline
color-coded pain rating scale. Red was chosen most frequently to represent severe pain. A lo-year-old girl with polyarticular arthritis illustrates the importance of
TABLE III
PERCENTAGE OF COLORS SELECTED ON PPQ INTENSITY RATING SCALE
Colors Pain intensity
None Mild Moderate Severe
Mosi /repen I !y selecred
Torul selecred
Orange
Blue
White
Black
Green
Yellow
Red
Purple
Yellow Orange Purple Red
(30) (30) (26) (52)
0 30 22 4
13 9 13 9 22 0 4 0
0 4 0 13 0 13 4 13
30 26 4 0
22 9 13 52 9 0 26 0
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TABLE IV
PERCENTAGE OF MOST FREQUENTLY SELECTED PAIN DESCRIPTORS
Pain descriptors Child Pain descriptors Parent
Sore
Aching Uncomfortable
Miserable
Tiring
Horrible
Pins and needles
70
65 65
52
4R
48
4x
Aching 70
Uncomfortable 57 Tiring 57
Sore 39 Miserable 30 Unbearable 30
TABLE V
COMPARATIVE PERCENTAGE OF SELECTED PAIN DESCRIPTORS
allowing the child to select the color/intensity match. This child chose red to represent no hurt, yellow to represent a little hurt, blue to represent more hurt, and green to represent a lot of hurt (no pain, mild pain, moderate pain, severe pain, respectively). Consistent with a diagnosis of polyarticular arthritis, she colored in with green (severe pain) both knees and her left temporomandibular joint. Both hands, wrists, shoulders and the right temporomandibular joint were colored in blue (moderate pain). Both elbows, feet and ankles were colored with yellow (mild pain). The rest of her body was colored in red (no pain). Thus, while red was selected to represent severe pain by 52% of the children, individual children should be given the opportunity to make their own developmentally appropriate color/intensity match. As demonstrated by this lo-year-old child, children can be very specific in identify- ing the various pain intensities of different sites by utilizing a color/intensity match with a body outline.
Sensory, affective and evaluative descriptor terms Table IV lists in descending order the most frequently chosen pain descriptor
terms by the children and their parents. Table V represents a comparative analysis of sensory, affective, and evaluative pain descriptor terms selected by the arthritic children in the present study in comparison to hospitalized (N = 100) and non- hospitalized (N = 114) children previously studied by Savedra et al. [18]. Sensory, affective and evaluative categories were based on Melzack [ll]. Pairwise compari- sons of the proportions of the number of words chosen by children with juvenile rheumatoid arthritis, hospitalized and non-hospitalized children, were performed using a 2 statistic for proportions. Because a large number of comparisons were being made, the Bonferroni inequality was used to control the family-wise type I error probability. No significant differences between any of the variables were found at the 0.05 level. This finding may be a function of lack of power due to a small sample size in the arthritis group.
Pain and emotion Table VI lists the emotions rated by the parents which appeared to influence the
child’s pain experience.
TABLE VI
DOES YOUR CHILD’S PAIN SEEM WORSE WHEN HE/SHE IS?
Emotion Percent yes
Tired 83
Upset 48
Unhappy 39
Anxious 30
Angry 26
Busy 22
Bored 17
Lonely 17
Arguing 13 Happy 4
TABLE VII
DOES YOUR (‘IIILD’S PAIN INTERFERE WITH TIiE FOI.LOWIN~; .AC‘TlVITII:S’
Activity Percent occurrcncc
Sports
Appetite
Sleeping Favorite activities
Schoolwork
School attendance
Friends
Unliked activities
Enjoying family
Reading
T.V.
Yes Sometime5 NO _____~..._.
65 13 22
44 17 3’)
43 22 35 31 17 51
26 26 4X
22 43 35 22 17 6 1 17 IX 65
13 3’) 4X
Y II 70
4 13 X3
Socio-environmental factors Table VII lists the activities which appeared to be influenced by the child’s pain
as selected by the child’s parent.
Discussion
While recent reviews indicate that pediatric acute and chronic pain are increas- ingly the target of cognitive-behavior therapy and research [26], comprehensive assessment of pediatric chronic pain is only now being systematically addressed. This initial study suggests that the Vami/Thompson Pediatric Pain Questionnaire represents a developmental step toward a more comprehensive view of the chronic pain experience in children. Further, for research purposes aspects of the self-report information from the PPQ may be validated by directly determining associated objective measures such as pharmacy records of prescribed analgesics, physical therapy performance, ambulation, school days missed, and hospitalizations [24].
The correlational and mean comparison data on the VAS between the child, parent and physician suggest that these 3 individuals were reliable raters of the child’s present and worst pain, and suggest the appropriateness of the developmen- tally modified VAS for use with a pediatric pain population. The relationship between present pain intensity and disease activity suggests that the VAS has construct validity, that is that the instrument does in fact measure self-perceived pain by the child. The color-coded pain rating scale provides a developmentally sensitive measure of pain severity and location. The pain descriptor terms begin the process of differentiating the sensory, affective and evaluative qualities of the pediatric pain experience. Finally, the PPQ also measures the socio-environmental and emotional factors which may influence pain perception and report. Un- questionably, this is an initial investigation with a very specific population of
37
children with chronic pain. However, it is hoped that the PPQ will undergo the same development process as the MPQ, being tested with larger numbers of children with a variety of acute and chronic pain experiences across a diversity of settings.
Acknowledgement
This investigation was supported in part by a grant from The Crippled Children’s Guild through the Behavioral Pediatrics Program at Or~opaedic Hospital.
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