Functional Measures in Children with Rheumatic Diseases

PEDIATRIC RHEUMATOLOGY

0031-3955/95 $0.00

+ .20

FUNCTIONAL MEASURES IN CHILDREN WITH RHEUMATIC DISEASES Kevin

J.

Murray, MB, BS, FRACP, and Murray H. Passo, MD

The rheumatic diseases affect children and the family in a multidimensional fashion, usually encompassing pain, physical disability, psychological distress, side effects of treatment, and economic burdens. For any clinician caring for such children, it is vital to be able to reliably measure the functional status of the patient as it compares with the activity and severity of their joint disease. In the broadest sense, we are interested in the effects of chronic disease on the intellectual, psychological, and social development of the child in addition to effects on physical function. Potential factors that may have as much effect on the functional outcome of a patient as the severity of the disease itself include (1) demographic variables such as area of residence, place of schooling, and educational level; (2) social supports of the family and child; (3) financial and emotional stability of the family; (4) access to health care, including physicians, allied health professionals, and medications; (5) previous health care experiences and preventive health strategies; (6) compliance with treatment regimens, and (7) attitudes towards health care. There are many reasons that pediatricians and rheumatologists are interested in the use of functional measures: (1) to allow us to obtain a "point in time" assessment of the patient's status; (2) to longitudinally track the effectiveness of therapeutic interventions; (3) to identify specific needs and concerns of patients and families; (4) to perhaps predict Dr. Murray was supported by a Saw Medical Fellowship from the University of Western Australia. This work was supported in part by the Children's Hospital Research Foundation of Cincinnati, the Schmidlapp Foundation, and the National Institutes of Health (AR42632). From the William S. Rowe Division of Rheumatology, Children's Hospital Medical Center, Cincinnati, Ohio

PEDIATRIC CLINICS OF NORTH AMERICA VOLUME 42 • NUMBER 5 • OCTOBER 1995

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outcome or prognosis early in the course of the disease; and (5) to maximize efficiency and minimize economic burden in a managed health care environment. A significant evolution in the area of functional assessment in rheumatic diseases has occurred in the last four decades since the World Health Organization stated that health is "not merely the absence of disease but complete physical, mental and social well being!"76 The emphasis of this article is on the development of outcome measures, which reflects the intimate relationship between functional measures and the outcome of our patients. The background to these developments is described, including the initial and current related work in the areas of general pediatrics and adult rheumatology. Next, the article discusses the use of adjunct instruments in pediatric rheumatology patients to assess specific dimensions of functional outcome, such as physical performance, pain assessment, psychosocial functioning, and impact on the family. Finally, the article focuses on instruments that have been developed to measure more broadly the health status and quality of life of rheumatic patients. A glossary (see Addendum) explaining the vocabulary is important to provide a foundation for a better understanding of the concepts within this article and provide a basis for further reading in this field as it evolves over the next several years. BACKGROUND TO THE DEVELOPMENT OF FUNCTIONAL OUTCOME MEASURES

Despite the best medical and psychosocial interventions, children with rheumatic diseases may still reach the same endpoint as those who go largely untreated (e.g., both may require total hip arthroplasty in their early adult years). The course of the disease by which they reach this outcome is important, however. This concept is illustrated in Figure 1. 60 It describes two possible clinical courses for a child with juvenile rheumatoid arthritis (JRA). The child eventually develops the same outcome with either course. In the first example, there is a rapid development of disability early in the course of the disease; this disability remains essentially unchanged thereafter. In the second case, the rate of progression during the initial years is slow; there is gradual accumulation of disability and then a more rapid deterioration in the latter years. Examination of the "area under the curve" rather than the endpoint illustrates the total burden of disability over time, indicating that the latter clinical situation is much more desirable. Moreover, the outcome may be postponed or prevented as improved treatments become available. To monitor the course of the disease effectively in this manner requires an instrument to measure functional status serially over time. The ideal instrument must be accurate, reliable, objective, sensitive to change, relevant to common daily functional activities, and administerable to children at all developmental ages (or to their parents as proxy). A hierarchical approach to the measurement of functional outcome

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A Disability

B

Disability

Figure 1. Comparison of two possible disease courses over time. A, The clinical course is represented by a child with the rapid development of functional disability that is sustained over time. B, The clinical course is represented by a child with the gradual development of functional disability and more rapid deterioration in later years. (Adapted from Symmons D: Quantifying progress in arthritis. Rep Rheum Dis 1:1-6, 1994; with permission.)

is illustrated in Figure 2. 24 The lowest or simplest level is represented by specific measurable parameters or functions related to a disease or its treatment; e.g., grip strength, ability to walk, pain, depression, and gastrointestinal side effects from drugs. The level above groups these parameters into the subdimensions of upper and lower limb function, general physical and psychological effects of disease, medical and surgical complications of treatment, and direct and indirect costs of the disease. The next level is condensed into five major dimensions: death, disability, discomfort or pain, iatrogenic complications, and economic impact. Specific instruments have been developed to measure some or

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Figure 2. A hierarchical approach to the measurement of functional outcome.· (From Fries JF: The assessment of disability: From first to future principles. Br J Rheum 22(suppl):4858, 1983; with permission.)

all of these dimensions. The ultimate or highest level of measurement is represented by a global outcome assessment. In effect, this is a summation, of all of the levels below into a single value. Physicians have tended to focus on the lower levels in this hierarchy, which are undoubtedly simpler to measure, but the highest levels are of greatest importance to the patient. Meenan addressed the conceptualization and measurement of health status with the pediatric rheumatology community in 1987.43 He eloquently outlines a similar hierarchical approach to the development of the health status assessment (Table 1). The major components of health status include physical health, symptoms, mental health, and social health. The subdomains of these components are included in the table. Meenan breaks down the process of developing an effective approach to a health status assessment into six steps. The first step is to specify the content of the instrument and the target population to be

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Table 1. MAJOR COMPONENTS OF HEALTH STATUS Physical health Physiologic health Growth and development Number of conditions Disease activity Functional status Mobility Manual performance Lesiure activities Instrumental activities of daily living Self-care activities of daily living Symptoms General Fatigue Insomnia Specific Shortness of breath Pain

Mental health Intellectual function Behavior Affect Anxiety Depression Communication Self-concept Social health Social support Social interactions Family relationships Peer relationships Social activity Role performance School Work Disability days

From Meenan RF: Health status assessment in pediatric rheumatology. Rheum Dis Clin North Am 13:133-140, 1987; with permission.

studied. This is particularly difficult in children because of their different developmental levels and the lack of general agreement in the concept of health status in children. Fortunately, since 1987 major developments in the adult rheumatology instruments have helped to provide a model that is of use to pediatric rheumatologists. The second major step in the development involves the task of developing the instrument. This includes the source of information, the focus of the questions, the response format, and the scoring. The third step requires documentation of the measurement properties of the instrument, including reliability, validity, precision, and generalizability. The last three steps in instrument development involve application, analysis, and revision. The instruments discussed in the following have all gone through these process steps, including feedback and improvement. Each of these instruments probably has taken in the range of 3 to 5 years in development and application work and additional years of feedback and revision. More recently, the concept of measuring quality of life has emerged; this is a higher order of outcome measurement. Some authorities in this research area suggest that the quality of life should be the primary focus of measurement, rather than specific dimensions of outcome as described earlier. Others suggest that quality of life can be suitably measured only by determining the opinions of patients and by supplementing (or replacing) the instruments developed by experts. 26 The measurement of health-related quality of life is a complex, multidimensional concept that is affected by many things other than the specific rheumatic disease being experienced by the patient. It is the matter of prime importance to the patients and their families. One of the earliest efforts to broadly address quality of life was the Medical Outcomes Study (MOS), which

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has been in widespread use in the greater medical community in recent years. 61 Other instruments to measure this highest level of patient outcome are being developed. w , 49, 54, 68 HEALTH OUTCOME INSTRUMENTS IN PEDIATRICS

Outcome instruments have been developed for the assessment and serial re-evaluation of chronically disabled patients in the pediatric subspecialties of neurology, rehabilitation, and developmental medicine. Table 2 is a partial list of instruments. The Functional Independence Measure for Children, or WeeFIM, was adapted from the original adult instrument (FIM) used in rehabilitation medicine. 27,52 This tool is administered by a trained observer to children from infancy to 7 years. It measures performance in the six domains: self-care, mobility, locomotion, communication, social cognition, and sphincter control, using a seven-point scale. The degree of assistance required by a caregiver in performance of these tasks or assistive devices also is assessed. The reliability and validity for this instrument have yet to be firmly established. The Tufts Assessment of Motor Performance was developed for children from 6 years to adult age who primarily have neurologic and developmental disability.25 It is a clinician-administered instrument that requires 1 hour of observation. It evaluates physical or motor capabilities in three domains: mobility, activities of daily living (ADLs), and communication skills. Approach, pattern, proficiency, and assistance required for performance are measured within each domain and incorporated into the overall result. The instrument has demonstrated good intraobserver reliability. The Pediatric Evaluation of Disability Inventory (PEDI) is a parent report instrument administered to chronically ill and disabled children. It was initially developed for children with chronic arthritis or spina bifida. 21 It examines the domains of mobility, .self-care, and social function and rates the need for caregiver assistance or environmental modifications. Early studies of validity have been encouraging. The Klein Bell Activities of Daily Living is a comprehensive tool developed for use in normal and cerebral palsy children. It can be administered to children of all ages. 34 This clinician-administered tool requires approximately 1 hour to complete. It examines 170 skill items, observing the child's performance in the domains of mobility, communication, eating, dressing, and bathing/hygiene. In a review of generic pediatric instruments, Gowland et al believed it to be a reliable and valid instrument in the population for which it was developed. 27 The Rand Health Insurance Study Scale is a parent report instrument designed for population screening of healthy children 0 to 13 years of age. 20 It examines performance in the areas of mobility, physical activity, role activity (performing tasks expected as a family member or class member at school), and self-care. This scale is a sensitive screening tool

Table 2. HEALTH OUTCOME INSTRUMENTS IN PEDIATRICS Instrument

Description

Administration

Functional Independence Measure for Children (WeeFIM)

Modified from adult tool (FIM) measuring burden of care in children (infancy to 7 years)

Physician

Tufts Assessment of Motor Performance

A comprehensive checklist of physical performance for ages 6 years to adult

Physician observation

Pediatric Evaluation of Disability Inventory (PEDI)

Tool for assessing success of rehabilitation in chronically disabled children

Parent report

Klein Bell ADL Scale

For assessing ADL function in children of all ages

Clinical observation

Rand Health Insurance Study

Population screening tool for ages 0-13 years

Parent report

Vineland Adaptive Behavior Scale

Developmental assessment tool for disabled children 0-18 years

Physician interview

Dimensions Examined

Reliability and Validity

Caregiver assistance required Self-care Mobility Locomotion Communication Social cognition Sphincter control Mobility Activities of daily living Communication Mobility Self-care Social function Functional mobility Communication Eating Dressing Hygiene Mobility Physical activity Role activity Self-care Communication Daily living skills Socialization Motor skills

Reliability but not validity demonstrated

Reliable

Reliability and validity well-established

Reliability and validity well-established

Reliable but poor discriminant validity

Good reliability and validity

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for large populations but has poor ability to discriminate between different degrees of disability or illness. The Vineland Adaptive Behavior Scale is a tool developed on a large population of disabled children. 27 This developmental test is administered in the form of a clinician interview based on parental report of performance in the areas of communication, daily living skills, socialization, and motor skills. It reportedly shows excellent reliability and validity.27

Although all of these measures have been used with arthritis patients, none have sufficient emphasis on the impact of joint stiffness; limitation of motion due to contractures and pain; details of specific hand function, neck movements, and ambulation, which may individually limit performance in a unique manner. In general, they do not examine the wider effects of the disease upon the psychological state of the individual child or the functioning of the family. Furthermore, none has been proved to be sensitive to changes in disease status or to have predictive value for functional outcome in rheumatic diseases. ASSESSMENT OF PAIN EXPERIENCE IN CHILDHOOD RHEUMATIC DISEASE

Pain is a common and important symptom in childhood rheumatic diseases and a major cause of disability. Early studies by Laakonsen and, later, Scott et al of pain in children with JRA found that children seemed to experience less pain related to joint disease compared to adults with RA.35,55 The authors, however, failed to take into account developmental differences between children and adults in conceptualizing pain and illness. Traditional "adult measures" of pain may not be adequate. Two subsequent studies of pain examined significant cohorts of children with JRA.7, 14 Only Beales et al7 used a specific questionnaire and took account of the effect of different cognitive developmental ages on pain perception or expression. Varni and Thompson et al were the first to systematically examine chronic pain in JRA70 by the development of the landmark Pediatric Pain Questionnaire (PPQ). This is the first instrument shown to be sensitive to cognitive and developmental conceptualizations of children. 72 It contains separate forms for parents, adolescents, and children. Adapted from the McGill Pain Questionnaire (MPQ),44 this tool uses a comprehensive list of 78 specific pain descriptors in four major categories to evaluate the qualities of the child's pain: sensory (such as aching, stinging, or squeezing), affective (punishing, cruel, or sickening), evaluative (uncomfortable, miserable, or unbearable), and miscellaneous sensory. The child is instructed to circle words from this list that most appropriately describe their pain experience. The PPQ established the use of the Visual Analogue Scale (VAS), which has subsequently been widely accepted as a reliable method of measuring pain. 73 The VAS measures both present pain and the worst pain in the last week. The

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scale is anchored from 0, signifying "no pain" (happy face for younger children) to 10, which indicates "severe pain" (sad face). In addition, a color-coded pain rating scale is used. Developmentally appropriate pain descriptors are matched to colors picked by the child. The children are then asked to use these colors to fill in a body figure indicating the parts in which they are experiencing pain. A PPQ parent form is completed. This elicits details about the child and family background and environment. The PPQ can be completed by a child in 20 to 30 minutes. The disease activity or s~verity index rating of the arthritis from remission, mild, moderate, severe, or incapacitating disease is usually obtained from the physician. It has been used with success in several studies of JRA patients and has been shown to be a valid and reliable too1. 62, 71, 73 Ross et al used a pain VAS in studying the validity of reported pain in 101 JRA patients and their parents. 53 They were able to demonstrate good correlation of parent and child pain ratings on the VAS; moreover, pain reports correlated with the subset of disease being greater in polyarticular versus pauciarticular disease and clinical disease activity. They concluded that the degree of pain reported can be an accurate indicator of the functional status of JRA patients. In a study of 30 children and adolescents with JRA, Jaworski et al used behavioral observation as an "objective" measure of pain experience. 31 Trained observers videorecorded specific pain behaviors during the performance of a standard protocol of activities. Good correlation was found between frequency of specific pain behaviors and observed levels of functional loss as well as parent and the child ratings of pain intensity. FUNCTIONAL OUTCOME INSTRUMENTS IN THE RHEUMATIC DISEASES

In 1949, Steinbrocker et al designed a classification for functional status that served as a "gold standard" in rheumatology for 40 years. 59 Table 3 lists the four levels of function, ranking patients from normal to Table 3. CLASSIFICATION OF FUNCTIONAL IMPAIRMENT Class I II III IV

Impairment Complete functional capacity ability to carry on all usual duties without handicaps Functional capacity adequate to conduct normal activities despite handicap of discomfort or limited mobility of one or more joints Functional capacity adequate to perform only little or none of the duties of usual occupation or self-care Largely or wholly incapacitated with patient bedridden or confined to a wheelchair, permitting little or no self-care

From Steinbrocker 0, Traeger CH, Batterman RC: Therapeutic criteria in rheumatoid arthritis. JAMA

140:659-662, 1949; with permission.

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completely incapacitated. Pediatric rheumatologists have employed this classification for outcome in drug trials and long-term prognosis of patients with JRA.39 This method, however, is relatively insensitive, particularly in Functional Class II. To illustrate this point, the following example contrasts two children with JRA. The first patient has involvement of only one knee with minimal discomfort but no active synovitis. He has a mild persistent 5 to 10 degree flexion contracture and cannot run as well as his peers. The second child has moderately severe polyarthritis with involvement of multiple joints and significant morning stiffness and takes 20 minutes to get dressed in the mornings. She is barely able to climb stairs and can only walk for a short time before resting because of pain. Both of these children would be in Functional Class II by the Steinbrocker classification, although obviously the former child has had a good functional status and the second has not. Lovell et al surveyed functional outcome in 1135 patients from seven pediatric rheumatology centers by using the Steinbrocker classification. 39 The classification was thought to be relatively indiscriminate; 95% of patients were characterized as being in Functional Class I or II with minimal impairment. Less optimistic results were reported by Wallace and Levinson74 and De Inocencio and Lovell,16 who collated data on JRA from their own experience and previous studies for the presence of continued active disease in JRA and functional status according to the Steinbrocker classification. The results of the 12 studies, which had follow-up ranging from 5 to 20 years, are listed in Table 4. The percentage of patients in Classes III and IV with significant or severe functional incapacity had a very wide range, from 9% to 48 %, in the different studies. Moreover, apart from a single study, the presence of continued active arthritis ranged from 31% to 55% (data not shown), implying that a significant number had or were likely to develop imTable 4. FUNCTIONAL OUTCOME OF JUVENILE RHEUMATOID ARTHRITIS Author Lindjnberg (1964) Michels et al (1987) Schaller and Wedgewood (1972) Hanson et al (1977) Renebohm and Correll (1984) Laakonsen (1966) Dequeker and Marjuadi (1982) Hill et al (1976) Ansell and Wood (1976) Stoeber (1981) Calabro et al (1976) Wallace and Levinson (1991)

Years of Follow-up (mean)

Steinbrocker Functional Class III or IV

5

22 17 12 28

5 7.5 10 >10 12 14 14.5 15 15 15 15-20

9 30 25 32 20 41.5 30 17

Adapted from Wallace CA, Levinson JE: Juvenile rheumatoid arthritis: Outcome and treatment for the 1990's. Rheum Dis Clin North Am 17:891-904, 1990; De Inocencio J, Lovell 0: Clinical and functional monitoring, outcome measures and prognosis of juvenile rheumatoid arthritis. Sallieres Clin Paediatr 1:769-801, 1993; with permission.

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paired functional capacity. These reports emphasize the relatively nondiscriminatory nature of this classification and the difficulty in monitoring change over time as assessed by statistical measures. In addition, there is a lack of focus on issues other than physical function. These problems fuelled the search for better measures of patient's overall functional status. SPECIFIC HEALTH OUTCOME MEASURES IN ADULT RHEUMATOLOGY

The 1980s saw the development of multiple functional assessment measures for adult patients with RA, largely in the form of self-administered questionnaires. Several instruments have achieved widespread acceptance. These include the Health Assessment Questionnaire (HAQ),23 the Arthritis Impact Measurement Scale (AIMS),41 and the McMaster Toronto Arthritis Patient Preference disability questionnaire (MACTAR).68 Several generic instruments developed for use in patients with any chronic disease have been used in studies of patients with RA with some success, but these are less widely accepted and validated in rheumatic populations. These include the Index of Well-Being,33 the Sickness Impact Profile,8 and the Functional Status Index. 32 In its original form, the HAQ is a comprehensive, self-administered questionnaire. It was initially developed using large groups of patients with RA. Subsequently, it has been used to assess patients with other chronic diseases. It has been administered to over 100,000 patients in clinical and research settings in several different countries with widespread acceptance.13, 51 The HAQ contains over 300 items covering five major dimensions of death, disability, discomfort, drug toxicity, and economic impact. It has undergone a number of modifications, and the shortened version uses 24 questions that focus on mobility and activities of daily living. The HAQ has the ability to detect both short-term and long-term changes in patient status both for RA and osteoarthritis. Pincus et al modified the HAQ (MHAQ) to incorporate an assessment of patient satisfaction and pain or discomfort. 49 The MHAQ can be easily completed in the office setting in 20 minutes. The reliability and validity of the HAQ and MHAQ are comparable. The AIMS is another self-administered questionnaire used to assess physical, social, and emotional well-being through 48 multiple choice questions. It can be completed within 10 to 20 minutes in the office setting. The responses are grouped to give scores for nine components of mobility, physical activity, dexterity or hand function, household activities and activities of daily living, social activity, anxiety, depression, and pain. There is also an overall or average score. It has been extensively used in a number of countries in both clinical and research forums with good reliability and validity.l A recent expansion of the instrument (AIMSII) incorporates measures of lower extremity function, patient preference and satisfaction, work status, income level, and comorbidity.42 The MACTAR is a more recently developed questionnaire designed

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for use in RA patients to measure quality of life and aspects of functional outcome. The instrument focuses on the activities most important to the patient in the domains of mobility, self-care, work, and leisure; changes that are most likely to affect functional outcome and quality of life. It is administered by a trained interviewer. The patients are asked to list specific activities limited by arthritis, ranking them by order in which the highest represents the activity they would most like to be able to perform without discomfort. At follow-up, only the top five disabilities are examined. The patients are asked if their ability to perform the task has changed and, if so, for better or worse. The instrument has demonstrated sensitivity to clinically important change in a controlled clinical trial of RA patients. 68 Its primary disadvantage is that important new disabilities may occur during the period of study and thus are unable to be included in the subsequent assessment. SPECIFIC HEALTH OUTCOME INSTRUMENTS IN CHILDHOOD RHEUMATIC DISEASES

The progress made in adult rheumatology measures in the last decade has prompted an awareness of the need for child-specific instruments to measure functional outcome in pediatric patients with rheumatic diseases. This need in part was stimulated in response to dissatisfaction with the older gold standard measures, which were relatively insensitive to functional changes, and to lack of applicability of the new adult instruments to children. Most reports have focused on the development of instruments for JRA, which constitutes the majority of pediatric rheumatology patients. Table 5 lists the current instruments, patient population for which each was developed, method of administration, dimensions and domains covered, style of instrument, estimated time for completion, and status of validation and reliability ratings. The first formal attempt to design an instrument for children was an adaptation of the AIMS, which has four dimensions of physical disability, psychological disability, pain, and social activity. Coulton et al developed the Childhood AIMS using the physical disability and pain dimensions only.ls The physical disability dimension included the domains of mobility, physical activities, dexterity, and ADL but excluded the section on household activities scale. The initial development study demohstrated good agreement (or convergent validity) with joint counts and subtypes of JRA (pauciarticular and polyarticular disease), but only moderate discriminant validity between active and inactive disease. The reliability and sensitivity of the instrument to important clinical change as assessed by other means were disappointing. 16, 39 Most children with JRA were able to adequately perform most of the activities within the domains of mobility, physical activity, dexterity, and ADL; only the "pain" scale demonstrated significant reliability over time. The Juvenile Arthritis Functional Assessment Scale (JAFAS) was developed by Lovell and a multidisciplinary pediatric rheumatology

Table 5. FUNCTIONAL STATUS MEASURES IN USE IN THE CHILDHOOD RHEUMATIC DISEASES Instrument

Development

Childhood Arthritis Impact Measurement Scale

77 children (2-17 yrs) with JRA from 250 clinic

Juvenile Arthritis Functional Assessment Scale Juvenile Arthritis Functional Assessment Report

71 JRA patients and 63 controls (7-18 yrs) 72 JRA patients (7-18

Description

Time to Complete

Dimensions

Reliability and Validity

Parent administered questionnaire for all ages

30-40 min

Physical disability Pain

Pain scale only reliable Poor discriminant validity

Trained observer record of 10 tasks in clinic setting Child and parent report questionnaire on 23 activities or ADLs

10 min

Physical

10 min

Physical

Good reliability and validity on initial report only to date Good reliability and validity on initial report only to date

Parent or self-administered questionnaire

<1 h

Parent administered questionnaire with 100 items

40-50 min

Self-report questionnaire containing 100 items

30 min

Parent report questionnaire containing >200 items

<1 h

Physical Pain Vision Global assessment Fine gross motor, psychosocial, pain, systemic symptoms Self-care Domestic Mobility School Physical Psyhosocial Pain Treatments

attenders

Childhood Health Assessment Questionnaire Juvenile Arthritis Quality of Life Questionnaire Juvenile Arthritis Self-report Index

Childhood Arthritis Health Profile

yrs) in rheumatology clinic 72 JRA patients (1-19 yrs)

40 JRA and spondyloarthropathy patients and parents Items generated from 11 children (8-18 yrs), parent and physicians JRA patients

Good reliability and validity only in initial study

Content validity demonstrated

Not available

Not available

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team in Cincinnati. 38 A range of tasks selected for children was adapted from the HAQ and AIMS. Specifically, the JAFAS involves ten tasks that evaluate the use of all the joints. The child is monitored and scored by a trained observer (usually a physical or occupational therapist). The child performs each of the tasks with standardized equipment. The instrument demonstrated excellent validity and reliability in its initial study and was easily administered in 10 minutes in a clinical setting. The limitation of the JAFAS was that it required standardized equipment and a trained observer to administer. The Juvenile Arthritis Functional Assessment Report for parents (JAFAR-P) or children (JAFAR-C) was subsequently developed29 (Table 6). It is a self- or parent-report questionnaire measuring a child's physical capabilities. This single set of questions was designed to be administered to children older than 7 years of age. Twenty-three simple tasks relevant to a child's basic daily activities are evaluated.· A three-point scale is used to assess whether a child is able to perform the task "all the time," "sometimes," or "almost never or none of the time." The results demonstrated excellent reliability and validity and did not vary in children older than 7 years. Strong correlations were found between parent's and children's reports of the child's abilities. Similarly, good correlation was found with the trained observer's assessment of the children with the JAFAS completed at the same time. Thus, the authors concluded that children and parents were reliable reporters, obviating the need for a trained observer and standardized equipment. The Childhood Health Assessment Questionnaire (CHAQ) is a parent- and/ or self-administered questionnaire adapted from the disability and discomfort dimensions of the HAQ by Singh et al in 1990.56-58 The initial development of this instrument involved a study of 72 consecutive children with JRA and their parents attending a pediatric rheumatology center. The questionnaire evaluates function in eight domains: dressing and grooming, arising from bed in the morning, eating, walking, hygiene, reach, grip, and general activities. The original HAQ was modified by the addition of at least one question to each domain, so that at least one qu~stion was relevant to a child of any developmental age. For example, the section on general activities would offer a range of items from capability to (1) run errands and shop, (2) get in and out of a car or toy car or school bus, (3) ride bike or tricycle, (4) do household chores, or (5) run and play. Each question is scored on a four-point scale from "able to complete without any difficulty" to "unable to do." Questions that are not appropriate for a particular age are not marked or scored. Each child is thus scored on an age-appropriate task, removing any developmental bias from the questionnaire. In each section, the question with the highest score (representing the greatest difficulty) is taken as the score for that functional area. If the child .requires assistance from another person or particular assistive devices such as crutches, wheelchair, "pen-grip," or "jar lid loosener," the score for that section is increased by a level of one. Three dimensions are measured by means of a VAS: pain, global

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FUNCTIONAL MEASURES IN CHILDREN WITH RHEUMATIC DISEASES

Table 6. THE JUVENILE ARTHRITIS FUNCTIONAL ASSESSMENT REPORT FOR CHILDREN

Patient Name:

Current Date:

Date of Birth: PART I

_

_ Ability Scale

"I'd like to ask you some questions about some things that have to be done: to eat, get dressed, and go to school. I want to know how well you've been able to do these things during the past week. Over the past week, have you been able to ... by yourself all of the time, just some of the time, or almost none of the time?" Responses are scored

0 1 2

for "All the time," for "Sometimes," and for "Almost never" All the time

Sometimes

Almost never

Item Scored

1. Take shirt off hanger 2. Button shirt 3. Pull on sweater over head 4. Turn on water faucet 5. Sit on floor, then stand up 6. Dry back with towel 7. Wash face with washcloth 8. Tie shoelaces 9. Pull on socks 10. Brush teeth 11. Stand up from chair without using arms 12. Get into bed 13. Cut food with knife and fork 14. Lift empty glass to mouth 15. Reopen previously opened food jar 16. Walk 50 feet without help 17. Walk up 5 steps 18. Stand up on tiptoes 19. Reach above head 20. Get out of bed 21. Pick up something from floor from standing position 22. Push open door after turning knob 23. Turn head and look over shoulder From Howe S, Levinson JE, Shear E, et al: Development of a disability tool for juvenile rheumatoid arthritis: The juvenile arthritis functional assessment report for children and their parents. Arth Rheum 34:873-880, 1991; with permission.

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assessment, and uveitis. The VAS for pain or discomfort is anchored from "no pain" at one end to "very severe pain" at the other. Respondents are asked to place a mark across the line representing their level of pain or discomfort during the last week. The CHAQ employs a VAS asking the parent or child to give a global assessment of the total impact of the arthritis, and another asking about the impact of eye disease (uveitis) on daily function. A final question addresses the need for medications in the previous 2 months. The internal reliability of the development study of the CHAQ was excellent and convergent validity was strong (there was agreement with other "gold standard" measures-Steinbrocker Functional Class, number of involved joints, and morning stiffness). The authors felt the CHAQ was "thus a reliable, valid and sensitive instrument for measuring the functional status in children with JRA."58 At McGill University in Montreal, Duffy et al recently reported the development of a new instrument called the Juvenile Arthritis Quality of Life Questionnaire (JAQQ).17-19 This self- or parent-report questionnaire was developed for use in children with chronic arthritis who are 2 years of age or older. In an initial report of its use, JAQQ contained 100 questions examining five dimensions: gross motor physical function, fine motor function (including grooming, dressing, feeding, and school functioning [Table 7]), psychosocial function (Table 8), systemic symptoms, and pain. Subsequent modifications reduced the number of items examined to 74. The dimension of psychosocial function includes questions on academic performance and peer group and teacher interactions at school. Emotional status, opinions, and feelings regarding the self are also examined. In each of the activities or tasks, the degree or frequency of difficulty caused by the rheumatic disease is rated on a six-point scale: (0 == not applicable, 1 == never, to 5 == all of the time). For the fine and Table 7. PHYSICAL FUNCTION-FINE MOTOR (FEEDING/SCHOOL-24 ITEMS) FROM THE JUVENILE ARTHRITIS QUALITY OF LIFE QUESTIONNAIRE

Feeding (12 items) Drinking from a cup Spreading butter with a knife Cutting with a knife Eating cereal with a spoon Eating with a fork Opening a can of pop Twisting of a bottle top Using a can opener Opening the refrigerator door Turning a door handle Chewing food Swallowing food

School (12 items) Writing with a pencil Writing with a ball point pen Using an eraser Drawing with a pencil Drawing with a crayon Painting with a small paintbrush Typing on a keyboard Using a computer Knitting Doing needlework Playing simple games Reading from a book

Data from Duffy C, Arsenault L, Duffy K: Level of agreement between parents and children in rating dysfunction in juvenile rheumatoid arthritis and juvenile spondyloarthritidies. J Rheumatol 20:213-219, 1993; with permission.

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Table 8. PSYCHOSOCIAL FUNCTION (26 ITEMS) FROM THE JUVENILE ARTHRITIS QUALITY OF LIFE QUESTIONNAIRE Miss school Do poorly academically Interact poorly with other children Interact poorly with siblings Interact inappropriately with parents Interact inappropriately with teacher Exhibit inappropriate behavior for age Fail to pay attention in class Fail to finish things Argue excessively with others Is mean to others Destroys own possessions Feels lonely

Cries for no apparent reason Overly demanding Disturbs class Disobeys parents Disobeys teacher Does not feel guilty after wrong doing Jealous of others Feels unloved Feels worthless Fights a lot Gets into trouble with authorities a lot Is teased a lot by classmates Feels sad

Data from Duffy C, Arsenault L, Duffy K: Level of agreement between parents and children in rating dysfunction in juvenile rheumatoid arthritis and juvenile spondyloarthritidies. J Rheumatol 20:213-219, 1993; with permission.

gross motor section, respondents are asked to choose the five activities with which the child has the greatest difficulty; this is an attempt to increase the test's sensitivity to change. Only the five selected items are scored in subsequent completions of the questionnaire. The systemic symptoms dimension is a checklist of common symptoms that may be associated with rheumatic diseases or their treatments, including poor appetite, mouth sores, skin rash, headache, joint stiffness, or pain. The dimension of pain assessment employs a VAS scale adapted in part from the Pediatric Pain Questionnaire developed by Varni et a1. 70 It is double-anchored, from 0, signifying "no pain" to 10, indicating "worst imaginable pain." This is accompanied by a verbal choice question asking respondents to choose the phrase that best expresses their pain (none, slight, moderate, severe, and extreme). For younger children, a "happy/ sad face" method is used to allow them to score their degree of pain. Subsequent use of the JAQQ has yielded evidence of good parent-child agreement across all areas examined. The instrument has been demonstrated to be a reliable method for either parent or child (> 9 years of age) to report on the impact of their arthritis on the quality of life, but it has yet to be widely used. 18, 19 The Juvenile Arthritis Self Report Index (JASI) was developed by Wright et al in 1992 at the Toronto Hospital for Sick Children. 77- 79 In part, this tool is an adaptation of the mentioned MACTAR, which was designed for use in adult arthritis patients. It is a self- or parentadministered questionnaire. The first of two sections comprise 100 questions that cover the dimensions of self-care, domestic tasks, mobility, school, and extracurricular activities. Each question asks how well the respondent would be able to perform a particular task today. Responses for each question use a seven-point scale, ranging from 0, representing the ability to perform tasks as easily as friends without JRA, to a maximum level of 6, representing a task that cannot be performed even

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with assistance from another person or special device. With equal weights given to the five dimensions, an overall total score out of a maximum of 100 is computed. This score corresponds to the child's current level of overall functioning. The second part of the JASI, the priority function section, represents an adaption of the MACTAR. The questions are reworded to be applicable to children and relate to home, school, and extracurricular activities. Five activities are chosen in which the child would most like to improve performance. The current ability on these activities is rated on a seven-point scale (from 0-6); the score increases in correspondence to the degree of difficulty or assistance required. In subsequent assessments, only these five activities are reassessed to attempt to increase the sensitivity to change of the questionnaire. The child or parent is asked if the ability to perform the task has changed, and if so, for better or worse. A numerical rating of the ability is again obtained. Although the JASI is a comprehensive instrument for assessing physical function, it does not assess pain, psychological issues, impact on the family, or economic costs of the rheumatic disease. Studies to demonstrate reliability or validity are under evaluation. Currently, a comprehensive questionnaire called the Childhood Arthritis Health Profile (CAHP) is being developed by Tucker et al at the New England Medical Center in Boston (personal communication).67 Again, a parent questionnaire format is used to assess the impact of arthritis on the child's health and well-being. The CAHP asks 55 questions that entail over 200 items about functioning related to the disease together with demographic data. The questions ask about activities and experiences in the previous 4 weeks and are broadly separated into two categories: issues related to the child's general health, and specific health problems related to JRA. The questions address in particular physical, emotional, social and school-work limitations; the quantity, frequency, and interference of pain with activities; psychosocial and behavioral issues with questions on "getting along" with others, moods, self-esteem, or satisfaction with self, others, and school; global questions on the nature and future expectations of the child's general health; general health of the parent or caregiver and impact of the child's health upon it; general symptoms suffered by the child; specific treatments used for JRA: medications, surgery, physical treatments (exercises, splinting), counselling (nutritional or psychological), and hospitalization; and demographic data, including employment of parents and relationships between family members, and the effects of the child's health on these factors. This instrument is in the early phases of study. To date, there are no data on reliability and validity available. When attempting to select an appropriate instrument for use, clinicians need to be aware of the specific domains they wish to assess. In the routine rheumatology outpatient clinic setting or in general pediatric practice, instruments such as the JAFAR or CHAQ are brief enough and can be completed by parents or children in the waiting room prior to an appointment. The results give an estimate of the functional level of the child at that time. It is likely these could be completed on a regular

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basis with reasonable reliability. When a comprehensive assessment is required, such as at the initial evaluation or on an annual or biannual basis, then the JAQQ and the JASI (and possibly the CAHP) offer more comprehensive assessment by evaluating multiple domains of interest. It is likely these will be most useful in tertiary care or research settings. If behavioral psychosocial or emotional concerns predominate, instruments designed specifically for these dimensions, as addressed in the next section, may be more appropriate. ASSESSMENT OF PSYCHOSOCIAL IMPACT ON CHILDREN AND FAMILIES

Psychosocial impact may be equally important as the severity of joint disease or physical disability in determining a child's adjustment to a chronic disabling condition. A brief review of recent developments and use of instruments in the area is important in the assessment of functional outcome. This topic has been thoroughly reviewed by several authors. 45,50 Early studies of JRA patients painted a rather pessimistic picture of psychosocial outcome but were largely anecdotal and retrospective. More recent studies, however, have found that, in general, the children do well in both psychological and social development and function. Several studies have identified significant social and emotional problems for children with JRA, but a substantial number of investigations examining similar issues do not identify problems in the same areas. For example, one observational study comparing peer relationships of children with JRA to classmates found no differences in social acceptance, sociability, aggression, or social isolation. 69 Similarly, investigations examining depressed mood and anxiety 9 and self-concept28, 69 have reported no excessive difficulties. It should be noted that some investigators have suggested that children may underreport feelings of anxiety or depressed mood due to disproportionate use of denial. Several studies looked at hospitalized children early in the course of their disease and therefore may not accurately reflect the situation after a number of years. This description of instruments in use is by no means exhaustive, but it does give a brief critical review of some of the available instruments, the dimensions they examine, and their use in children with rheumatic diseases. These are used in the context of clinical research and do not have practical applicability in the office. Piers Harris Self Concept Scale

The Piers Harris Self Concept Scale48 consists of 80 statements about the self-concept to which a subject responds with yes or no answers to yield a total score representing the degree of positive self-concept. Ivey et al used this tool to demonstrate no difference between JRA patients

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with mild and severe disease. 3o Similarly, in 1988, Ungerer et al examined 363 children and young adults with JRA and were unable to demonstrate any significant difference between children with JRA and healthy children. 69 Child Behavior Checklist

The Child Behavior Checklist2 (CBCL) developed by Achenbach and Edelbrook is a well-standardized instrument that has been used extensively in different populations of children. Good reliability and validity have been reported. It is a parent-report questionnaire that examines "externalizing" behaviors (aggression, conduct disorder, delinquency, hyperactivity, and cruelty) and internalizing behaviors (depression, anxiety, withdrawal, and somatic complaints). It emphasizes problematic behaviors and competency in school peer-related and social activities. The CBCL was useq in a study by Ross and Lavigne et al,53 who demonstrated that psychological variables have a substantial impact on the reporting of pain in children with JRA after controlling for the contribution of disease. Health and Daily Living Scale

This self-report questionnaire47 measures health-related psychosocial functioning in adolescents and adults. It includes a section for reporting on psychosocial functioning of children within the family, allowing four composite indices to be developed: (1) physical health problems, (2) psychological health problems, (3) behavioral problems, and (4) health-risk behaviors. Timko et al used the HDL scale in a study of adaption to rheumatic disease that compared 165 JRA patients to their healthy siblings. 65 They also examined for differences between groups with mild versus severe disease or disability. This study found that significant adjustment difficulties occurred in the dimensions of social, psychological, and family functioning and were worse in patients with more severe disease. Family Environment Scale

The Family Environment Scale46 tool contains three subscales that measure cohesion (the degree of commitment, help, and support among family members), expressiveness or the extent to which family members act openly and express their feelings directly, and conflict (reflecting the amount of openly expressed anger, aggression, and conflict among family members). This scale was employed by Timko et al in a study of 172 children with rheumatic disease and their parents. They demonstrated the existence of parental risk and resistance factors measured at baseline

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that could explain the quality of the children's adaption to their chronic illness 4 years later. 64 Parents' personal strain and depressed mood and fathers' drinking problems were associated with poor adjustment, whereas fathers' social functioning enhanced adaption. ECONOMIC IMPACT OF JRA

The ideal functional assessment instrument would include a measure of the economic impact on the individual and its consequences to the overall outcome. Two reports examined the question of economic impact on families of children with rheumatic disease. McCormick et al surveyed 138 families and documented out-of-pocket expenses of $548 per year on average; these were related to hospitalizations not covered by third-party payors. 40 Greater than 50% of patients reported difficulty in meeting these extra costs. Visits to physicians and purchases of medicines increased these expenses significantly for most families. Allaire et al developed a specific questionnaire to quantitate the direct family and community costs of 120 children with JRA, including those related to hospitalization and outpatient care. 3 The mean annualized direct cost was $7905. Family out-of-pocket medical costs averaged $708 for outpatient care, with total "family costs" of $1524 per year, including salary loss and nonmedical expenses. This sum represented an average of 5% of family income. Evaluation of economic burden needs to be included in a comprehensive functional assessment instrument of the future. FUNCTIONAL MEASURES IN OTHER CHILDHOOD RHEUMATIC DISEASES

Few studies have examined the diseases of lupus, scleroderma, or dermatomyositis in terms of functional outcome in any detail. The numbers of patients seen in anyone pediatric center are relatively few, which hampers efforts to develop specific instruments. Instruments developed for use in JRA patients could be used in such diseases, particularly when musculoskeletal or arthritic symptoms predominate. Adaptions will probably be required to take into account the unique features of each disease. The Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) is a global measure of disease activity. It includes assessment of clinical and laboratory parameters. 12 Similarly, the Systemic Lupus Activity Measure (SLAM) is designed to assess current activity of disease in SLE and is based on specific clinical disease features. 37 Neither tool, however, measures accumulated damage or health status specifically. Both have been reported to have been used reliably in groups of adult patients, but no pediatric use has been reported. In general, a number of systematic methods for assessing and recording muscle strength, disease activity, and functional level in the

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inflammatory muscle diseases and in neuromuscular disease have been used on an ad hoc basis. No specific tool has been reported for use in children with inflammatory muscle diseases, but Feldman et al recently reported on the use of the CHAQ in 37 children with dermatomyositis. 22 The CHAQ was shown to be a valid and sensitive tool in the evaluation of functional outcome of the patients, although none had more than mild calcinosis or contractures. Development or adaption of a standardized tool will be essential to study patients in a uniform fashion for longitudinal outcome research. NEW DEVELOPMENTS

Some new concepts are being embraced by those interested in measuring functional outcome of patients. Utilities are generic measures of health-related quality of life that focus on patient preferences for alternative health conditions. 63 Utilities in this context are estimates of the willingness to accept risks to achieve a certain outcome (e.g., the possibility of remission from a new cytotoxic agent with a high risk of serious side effects). With these measures, patients reduce positive and negative aspects of their disease into a single cardinal value that reflects their global health-related quality of life. Standard gamble is a technique to ascertain the value patients ascribe to their own current health status versus complete health and how much they are willing to gamble to achieve these outcomes ahead of time. Utility questionnaires take up to 1 hour to administer with trained interviewers. They are useful for comparisons between study groups or for cost-benefit analyses that use quality adjusted life years attributed to a particular treatment or health care program. They are being used in clinical trials of therapeutic interventions in patients with rheumatic diseases, with some acceptance. 6,11 In pediatrics, the concept has been applied to a study of extremely low birth weight babies compared to controls. It has helped to demonstrate the overall long-term burden experienced by these children. 54 The application of this area to the care of children is fraught with difficulty. Parents have to be willing to gamble as proxies on their children's behalf. In a sense, they do this with choosing current treatment regimens and placing a value on the different outcome states for their children. Parental values and interpretation of the effects of disease or pain may differ widely from their children (including children with rheumatic diseases). The development of these measures and possible applications to the pediatric population is an area requiring future research. CONCLUSIONS

The area of functional assessment in children with rheumatic disease recently has attracted much needed effort and attention. Physicians

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caring for these children can select from several instruments to assess their patients' functional outcome. Tools are being developed to assess the full impact of these diseases on the family, including economic and psychosocial domains. The ultimate goal is improving the quality of life of the child and family. Instruments to measure quality of life that incorporate patient preference represent an important step in the evolution of outcome assessment but are in early phases of development. Most agree that the development of these instruments is of paramount importance, but certain limitations must be realized. The lengthy comprehensive questionnaires are less applicable to patients or primary care physicians in office settings and will be most heavily used in tertiary care and the research field. Although no ideal single instrument exists, and none of the available instruments has been uniformly accepted, physicians do have a number of useful tools from which to choose to facilitate the care of children with rheumatic disease and assess the impact of their interventions. Work on development of these and newer, perhaps composite, instruments continues under the auspices of the American Academy of Pediatrics in both rheumatology and orthopedic sections, which have formed working committees to address this area. As our knowledge of the strengths and limitations of various measures continues to expand, we will become more adept at selecting the most appropriate measure given the unique demands of particular situations. We hope that they help us to achieve the real goals of medicine or desires of our patients and their families, which have been stated as 24 (1) to be alive as long as possible; (2) to be functioning normally; (3) to be free of pain and other physical, psychological, or social symptoms; (4) to be free of iatrogenic problems from the treatment regimen; and (5) to maximize growth and development so as to be independent adults. To this we would add maximal efficiency and reduced economic impact to the patient and their community. ACKNOWLEDGMENT The typing and secretarial assistance from Sonya Fagaly of the Division of Rheumatology is greatly appreciated.

References 1. Abello-Banfi A, Cardiel MH, Ruiz-Mercado R, et al: Quality of life in rheumatoid arthritis: Validation of a Spanish version of the Arthritis Impact measurement scales (Spanish-AIMS). J Rheumatol 21:1250-1255, 1994 2. Achenbach TM, Edelbrock CS: Manual for the Child Behavior Checklist and Revised Behavior Profile. Burlingham University Associates in Psychiatry, Burlington, VT, The University of Vermont, 1983 3. Allaire SH, DeNardo BS, Szer IS, et al: The economic impacts of juvenile chronic arthritis. J Rheumatol 19:952-955, 1992 4. American College of Rheumatology: Dictionary of the Rheumatic Diseases III. Health Status Management, Contact Associates International Ltd., Bayport, NY, 1988

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5. Ansell BM, Wood PH: Prognosis in juvenile chronic polyarthritis. Clin Rheum Dis 2:397-413, 1976 6. Bakker C, Rutten-van Mulken M, Hidding A, et al: Patient utilities in ankylosing spondylitis and the association with other outcome measures. J Rheumatol 21:12981304, 1994 7. Beales JG, Keen JH, Holt PJ: The child's perception of the disease and the experience of pain in juvenile chronic arthritis. J Rheumatol 10:61-65, 1983 8. Bergner M, Bobbit RA, Pollard WE, et al: The Sickness Impact Profile: Validation of a health status measure. Med Care 14:57-67, 1976 9. Billings AG, Moos RH, Miller H, et al: Psychosocial adaptation in juvenile rheumatic disease: A controlled evaluation. Health Psychol 6:343-359, 1987 10. Blalock SJ, Sauter V, DeVellis RF: The Modified Health Assessment Questionnaire. Arthritis Rheum 3:182-188, 1992 11. Bombardier C, Ware J, Russell J, et al: Auranofin therapy and quality of life. Am J Med 81:565-578, 1986 12. Bombardier C, Gladman D, Urowitz M, et al: Derivation of the SLEDAI: A disease activity index for lupus patients. Arth Rheum 35:630-640, 1992 13. Bruhlmann P, Stucki G, Michel BA, et al: Evaluation of a German version of the physical dimensions of the Health Assessment Questionnaire in patients with rheumatoid arthritis. J Rheumatol 21:1245-1249, 1994 14. Burckhardt C: The use of the McGill Pain Questionnaire in assessing arthritis pain. Pain 19:305-314, 1984 15. Coulton C, Zborowsky E, Lipton J, et al: Assessment of the reliability of the Arthritis Impact Scales for children with juvenile arthritis. Arthritis Rheum 30:819-824, 1987 16. De Inocencio J, Lovell DJ: Clinical and functional monitoring, outcome measures and prognosis of juvenile rheumatoid arthritis. Baillieres Clin Paediatr 1:3:769-801, 1993 17. Duffy CM, Arsenault L: The juvenile arthritis quality of life questionnaire - A responsive index for chronic childhood arthritis. Arthritis Rheum 35(suppl):S222, 1992 18. Duffy CM, Arsenault L, Duffy KNW, et al: Validity and sensitivity to change of the Juvenile Arthritis Quality of Life Questionnaire. Arthritis Rheum 36(suppl):S144, 1993 19. Duffy CM, Arsenault L, Duffy K: Level of agreement between parents and children in rating dysfunction in juvenile rheumatoid arthritis and juvenile spondyloarthritidies. J Rheumatol 20:213-219, 1993 20. Eisen M, Ware JE: Measuring components of children's health status. Med Care 17:902-921, 1979 21. Feldman AB, Hayley SM, Corgell J, et al: Concurrent and construct validity of the Pediatric Evaluation of Disability Inventory. Phys Ther 70:602-610, 1990 22. Feldman BM, Ayling-Campos A, Luy L, et al: Measuring disability in Juvenile Dermatomyositis: Validity of the Childhood Health Assessment Questionnaire. J Rheumatol 22:326-331, 1995 23. Fries JF, Spitz PW, Young DY: The dimensions of health outcomes: The Health Assessment Questionnaire, Disability and Pain Scales. J Rheumatol 9:789-793, 1982 24. Fries JF: The assessment of disability: From first to future principles. Br J Rheum 22(suppl):48-58, 1983 25. Gang BM, Haley SM, Hallenborg SC, et al: Description and inter observer reliability of the Tufts Assessment of Motor Performance. Am J Phys Med Rehabil 67:202-210, 1989 26. Gill TM, Firestein AR: A critical appraisal of the Quality-of-Life measurements. JAMA 272; 8:619-626, 1994 27. Gowland C, King G, King S, et al: Review of selected measures in neuro-developmental rehabilitation. Research report of 91-2 Neuro-developmental Clinical Research Unit. Hamilton, OH, Chedoke McMaster Hospitals, 1991 28. Harris JA, Newcomb AF, Gewanter HL: Psychosocial effects of juvenile rheumatic disease. Arth Care Res 4:123-130, 1991 29. Howe S, Levinson JL, Shear E, et al: Development of a disability tool for juvenile rheumatoid arthritis: The Juvenile Arthritis Functional Assessment Report for children and their parents. Arth Rheum 34:873-880, 1991 30. Ivey J, Brewer EJ, Giannini EH: Psychosocial functioning of children with juvenile rheumatoid arthritis (abstr). Arth Rheum 24(suppl):S100, 1981

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31. Jaworski JM: Development of an observation method for assessing pain behavior in children and adolescents with JRA (abstr). Arthritis Rheum 34(suppl):S82, 1991 32. Jette AM: Functional Status Index: Reliability of a chronic disease evaluation instrument. Arch Phy Med Rehabil 61:395-401, 1980 33. Kaplan RM, Bush JW, et al: Health status: types of validity for an index of well being. Health Serv Res 11:478-507, 1976 34. Klein RM, Bell B: Self care skills: Behavioral measurement with the Klein Bell ADL Scale. Arch Phys Med Rehab 63:335-338, 1982 35. Laakonsen A: A prognostic study of juvenile chronic arthritis: Analysis of 544 cases. Acta Paediatr Scand (Suppl)166:9-103, 1966 36. Liang MH, Larson MG, Cullen KE, et al: Comparative efficiency and sensitivity of five health status instruments for arthritis research. Arthritis Rheum 28:542-549, 1985 37. Liang MH, Socher SA, Larsen MG, et al: Reliability and validity of 6 systems for the clinical assessment of disease activity in SLE. Arthritis Rheum 32:1107-1118, 1989 38. Lovell DJ, Howe S, Shear E, et al: Development of a disability tool for juvenile rheumatoid arthritis: The Juvenile Arthritis Functional Assessment Scale. Arthritis Rheum 32:1390-1395, 1989 39. Lovell DJ: Newer functional outcome measures in juvenile rheumatoid arthritis. J Rheumatol 19:2831, 1992 40. McCormick M, Stemmler MM, Athreya BH: The impact of childhood rheumatic diseases on the family. Arthritis Rheum 29:872-879, 1986 41. Meenan RF, Gertman PM, Mason JH, et al: Measuring health status in arthritis: The Arthritis Impact Measurement Scales. Arthritis Rheum 23:146-152, 1980 42. Meenan RF, Mason JH, Anderson JJ, et al: AIMSII. The content and properties of a revised and expanded AIMS (abstr). Arthritis Rheum 33(suppl):S15, 1990 43. Meenan RF: Health status assessment in pediatric rheumatology. Rheum Dis Clin North Am 13:133-140, 1987 44. Melzack R: The McGill Pain Questionnaire: major properties and scoring methods. Pain 1:277-299, 1975 45. Miller JJ: Psychosocial factors related to rheumatic diseases in childhood. J Rheumatol 20:1-11, 1993 46. Moos RH, Moos BS: Family Environment Scale Manual. Palo Alto, Consulting Psychologists Press, 1986 47. Moos RH, Cronkite RC, Finney JW: Health and Daily Living Form Manual, ed 2. Palo Alto, Center for Health Care Evaluation, Veterans Affairs and Stanford University Medical Centers, 1990 48. Piers Harris Children's Self-Concept Scale. Los Angeles, Western Psychological Services, 1984 49. Pincus T, Summey JA, Soraci SA, et al: Assessment of Patient Satisfaction in activities of daily living using the modified Health Assessment Questionnaire. Arthritis Rheum 26:1346-1353, 1983 50. Quirk ME, Young MH: The impact of JRA on children, adolescents and their families. Arth Care Res 3:36-43, 1990 51. Ramey DR, Raynauld JP, Fries JF: The Health Assessment Questionnaire 1992. Arthritis Care Res 5:119-129, 1992 52. Research Foundation-State University of New York: Guide for the use of the uniform data set for medical rehabilitation including the functional independence measure for children (WeeFIM). Buffalo, New York, State University of New York, 1991 53. Ross CK, Lavigne JV, Hayford JR, et al: Psychological factors affecting reported pain in juvenile rheumatoid arthritis. J Ped Psychol 18:561-573, 1989 54. Saigal S, Feeney D, Furlong W, et al: Comparison of health related quality of life of extremely low birth weight babies and a reference group of children at eight years of age. J Pediatr 125:18-25, 1994 55. Scott PJ, Ansell BM, Huskinson EC: Measurement of pain in juvenile chronic polyarthritis. Ann Rheum Dis 36:186-187, 1977 56. Singh G, Athreya B, Fries J, et al: Measurement of functional status in juvenile rheumatoid arthritis (abstr). Arthritis Rheum 33(suppl 9):S15, 1990 57. Singh G, Brown A, Athreya B, et al: Functional status in juvenile rheumatoid arthritis:

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sensitivity to change of the childhood health assessment questionnaire (abstr). Arthritis Rheum 34(suppl 9):581, 1991 Singh G, Athreya BH, Fries JF, et al: Measurement of health status in children with juvenile rheumatoid arthritis. Arthritis Rheum 37;12:1761-1769, 1994 Steinbrocker 0, Traeger C, Batterman R: Therapeutic criteria in rheumatoid arthritis. JAMA 140:659-662, 1949 Symmons D: Quantifying progress in arthritis. Rep Rheum Dis Topical Rev (series 3):1:1-6, 1994 Tarlov AR, Ware JE, Greenfield 5, et al: The Medical Outcomes Study-an application of the methods for monitoring the results of medical care. JAMA 262;7:925-930, 1989 Thompson KL, Varni JW, Hanson V: Comprehensive assessment of pain in juvenile chronic arthritis: An empirical model. J Pediatr Psychol 12:241-255, 1987 Thompson MS: Willingness to pay and accept risks to cure chronic disease. Am J Public Health 76:392-396, 1986 Timko C, Baumgartner M, Moos RH, et al: Parental risk and resistance factors among children with juvenile rheumatic disease: A four year predictive study. J Behav Med 16:571-588, 1993 Timko C, Stovel KW, Moos RH, et al: Adaption to juvenile rheumatic disease: A controlled evaluation of functional disability with a one year follow-up. Health Psychol 11:67-76, 1992 Torrance GW: Utility approach to measuring health related quality of life. J Chronic Dis 40:593-600, 1987 Tucker, et al: The Childhood Arthritis Health Profile (private communication-the questionnaire). New England Medical Center, Boston, MA, 1994 Tugwell P, Bombardier C, Buchanan W, et al: The MACTAR Patient Preference Disability Questionnaire: an individualized approach for addressing improvement in physical disability in clinical trials in rheumatoid arthritis. J Rheumatol 14:446-451, 1987 Ungerer JA, Chaitow J, Champion GD: Psychosocial functioning in children and young adults with juvenile arthritis. Pediatrics 81:195-202, 1988 Varni JW, Thompson KL, Hanson V: The Varni/Thompson Pediatric Pain Questionnaire 1. Chronic musculoskeletal pain in juvenile rheumatoid arthritis. Pain 28:27-38, 1987 Varni JW, Thompson-Wilcox K, Hanson V, et al: Chronic musculoskeletal pain and functional status in juvenile rheumatoid arthritis: An empirical model. Pain 32:1-7, 1988 Varni JW, Bernstein BH: Evaluation and management of pain in children with rheumatic diseases. Rheum Dis Clin North Am 17:985-999, 1991 Walco GA, Varni JW, Ilowite NT: Cognitive behavioral management in children with juvenile rheumatoid arthritis. Pediatrics 9:1075-1079, 1992 Wallace CA, Levinson JE: Juvenile rheumatoid arthritis: outcome and treatment for the 1990's. Rheum Dis Clin North Am 17:891-904, 1990 Ward MM: Clinical measures in rheumatoid arthritis: which are most useful in assessing patients? J Rheumatol 21:17-21, 1993 World Health Organization: The First Ten Years of the World Health Organization. Geneva, WHO, 1958 Wright FV, Law M, Crombie V, et al: Development of a self report functional status index for juvenile rheumatoid arthritis. J Rheumatol 21:536-544, 1994 Wright V, Crombie V, Law M, et al: Development of a self report functional index for children and teens with juvenile arthritis (abstr). J Rheumatol 19(suppl 33):S125, 1992 Wright V, Law M, Crombie V, et al: The Juvenile Arthritis Self Report Index (personal communication-The Manual). unpublished, 1992

Address reprint requests to Murray H. Passo, MD Division of Rheumatology Children's Hospital Medical Center 3333 Burnet Avenue Cincinnati, OH 45229

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Glossary of Terms Used in Functional Assessment Literature

A glossary explaining the vocabulary is important to provide a foundation for a better understanding of the concepts within this article and provide a basis for further reading in this field as it evolves over the next several years. Dimension A major discrete subsection within overall health status; such as physical abilities, pain level, drug side effects, emotional status, and psychosocial impact. Disability index A score or number usually derived from a summation of the various domains of physical function within an assessment tool. It reflects the overall level of a patient's physical disability at a single point in time. Domain A subsection of a dimension that describes a discrete area of function: Le., a group of specific items that examine closely related areas of functioning such as ambulation, hand function, and social activities within the physical abilities dimension. Functional outcome A broad summary assessment of the current status of a person with respect to the effect of a disease on their expected ability to function in physical, psychological, and economic terms. Health status An overall point estimate of a person's well-being in physical, psychological, and social terms compared to the normal population or to a previous measurement. 4 ~, Process variables Specific objectively measurable" aspects of a patient's disease, such as acute phase proteins, C reactive protein or erythrocyte sedimentation rate, joint count (tenderness and/or swelling), duration of morning stiffness, radiographic changes, 25-meter walking time, and grip strength. Quality of life (or health-related quality of life) A global personal assessment of all the dimensions of health, including physical functional status, cognitive and social functioning, life satisfaction, and overall health status. It includes the implication of an assessment or value that a person attaches to their current health status. Reliability The extent to which a scale or instrument will yield similar answers if administered to the same observer repeatedly (intraobserver reliability) or to different observers (interobserver reliability) at the same time. Responsiveness The ability of an instrument to detect clinically important change over time in the dimension being measured. Standard gamble A statistical concept or technique usually used to obtain utility measurements that describe what a person is willing to do or to undergo (such as experimental therapy) or gamble to achieve a specified state (i.e., perfect health) with a specified risk of death or severe disease state as the alternative. Utilities Generic health-related quality of life measures that assess the value or preference that patients attach to a particular overall health status (such as complete health, current level of well-being, or death).66 Validity An expression of an instrument's ability to measure what it is intended to measure. Face validity requires that a measure appear sensible (particularly important in child scales, which are dependent on development). Convergent validity is the agreement with another gold standard" or well accepted measure of a similar nature. Discriminant validity is the ability of 1/

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MURRAY & PASSO

an instrument to discriminate disease from health or between different forms of disease or levels of disease activity. Willingness to pay An assessment of the amount a person (or parent) is willing to pay (or forego) to achieve a certain health outcome, such as freedom from pain, improved mobility, or functional independence. 63