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Keywords:

  • Juvenile idiopathic arthritis;
  • Functional assessment;
  • Disability;
  • Health outcomes

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. REFERENCES
  9. APPENDIX A
  10. Supporting Information

Objective

To develop and validate a new short and simple measure of physical function in children with juvenile idiopathic arthritis (JIA).

Methods

The Juvenile Arthritis Functionality Scale (JAFS) is a 15-item questionnaire that explores physical function in 3 body areas (lower limbs, hand/wrist, and upper segment). Validation of the Italian version of the instrument was accomplished by evaluating 211 consecutive JIA patients ages 2.2–18 years. The instrument's feasibility, face and content validity, construct and discriminative ability, internal consistency, interrater reliability, and responsiveness to clinical change were examined. JAFS psychometric properties were compared with those of the Childhood Health Assessment Questionnaire (C-HAQ).

Results

The JAFS was found to be feasible and to possess both face and content validity. The JAFS score correlated with most of the other JIA outcome measures in the range predicted, thereby demonstrating good construct validity, and discriminated well among different levels of disability. The internal consistency (Cronbach's alpha) was 0.82. The intraclass correlation coefficients between raters (mothers, fathers, and children) and between reported and observed level of function ranged from 0.65 to 0.84. The JAFS revealed fair responsiveness, with a standardized response mean ranging from 0.42 to 0.56. Comparison with the C-HAQ indicated that the JAFS may be superior in terms of construct validity and reliability, and at least as good in terms of discriminant validity and responsiveness.

Conclusion

The JAFS exhibited good reliability, construct validity, and discriminative ability and fair responsiveness, and is therefore a valid instrument for the assessment of physical function in children with JIA.


INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. REFERENCES
  9. APPENDIX A
  10. Supporting Information

The assessment of physical function is a fundamental component of the clinical evaluation of children with juvenile idiopathic arthritis (JIA) (1, 2). Currently, the most widely used functional status tool is the Childhood Health Assessment Questionnaire (C-HAQ) (3). This instrument is often chosen to serve as a core response variable in clinical drug trials (4). The C-HAQ is thought to have several advantages over other pediatric measures of physical function, which include multidimensionality, applicability to children of all ages, and availability of translation in a number of different languages (5). The C-HAQ has been shown to have excellent reliability and validity, good discriminative properties, and fair responsiveness to clinical change over time (6–10).

Despite its success, however, the C-HAQ has remained essentially a research tool and is not routinely administered in most pediatric rheumatology centers. Many reasons may explain why the C-HAQ is uncommonly incorporated in standard clinical care. One reason is that it is long. The C-HAQ comprises 30 questions concerning activities of daily living, 14 questions relating to the use of aids or devices, and 8 questions concerning activities in which assistance of another person is required, resulting in a total of 52 questions. The scoring system is somewhat complex and requires a calculator to compute the score. Because the questionnaire involves 2 sides of 1 page, it cannot be quickly reviewed by a clinician to obtain a simple overview of the patient's status. Furthermore, in our experience some questions, particularly those concerning the activities in which the child needs help from another person, are occasionally not answered correctly or are misunderstood.

These considerations have led us to develop a shorter and simpler questionnaire for the assessment of physical function in standard clinical care of children with JIA. In this report, we describe the development of the new instrument, the Juvenile Arthritis Functionality Scale (JAFS), and provide evidence of its validity by comparing its psychometric properties with those of the C-HAQ.

PATIENTS AND METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. REFERENCES
  9. APPENDIX A
  10. Supporting Information

Development of the JAFS.

The JAFS was devised by a group of 6 experienced pediatric rheumatologists (AR, SV, AB, NR, SM-M, and AM) based on their previous clinical experience, as well as on existing measures of pediatric function (3, 11–15). The panel selected a range of tasks (functions; n = 36) that required the use of all joints and joint groups and could be performed by children of all ages. Each task had to be simple to score by patients/parents, objectively measurable, and relevant to common daily functions. Furthermore, it was established a priori that the questionnaire should explore in greater detail the function of the joints and joint groups that are involved more frequently in JIA and are more important to children's function. Three main functional areas were identified (lower limbs, hand/wrist, and upper segment), which were designated to have an equal weight in the instrument scoring system. After extensive discussion of the relative importance of each potential task, a task was retained only when there was agreement that it should be kept in the questionnaire. This led to a reduction of the number of items to 20. Thus, content validity was obtained by the members of the group. To ensure face validity, the questionnaire was shown to 12 physicians (4 pediatric rheumatologists, 2 orthopedic surgeons, and 6 residents in pediatrics) who were not part of the JAFS group and to 4 physiotherapists, and their opinion on the suitability of the instrument was asked. Although all agreed on the questionnaire, several points were raised regarding definition of tasks, which were discussed and partially incorporated in the final version. A pilot test in a convenience sample of 20 patients with JIA and in a control group of 54 healthy children ages 2–14.6 years was performed. Except for 2 patients on 1 and 2 items, respectively, all healthy children were reported or observed to be able to perform every task. After these tests, the list was further reduced to 15 tasks. An item was considered for deletion if 1) it proved difficult to administer, 2) the control population demonstrated difficulty in completing the task, or 3) there was no variability in performance between the JIA and control population.

The 15-item questionnaire that emerged from the analyses is presented in Appendix A (available online at the Arthritis Care & Research Web site at http://www.interscience.wiley.com/jpages/0004-3591:1/suppmat/index.html). Items were grouped into 3 functional areas, each composed of 5 items: lower limbs, hand/wrist, and upper segment. The ability of the child to perform each task is scored as follows: 0 = without any difficulty, 1 = with difficulty, and 2 = unable to do. Questionnaire completers are asked to note only those difficulties that are caused by arthritis. An “unable to perform” column is included to designate the functions that cannot be performed because of developmental immaturity. The total score ranges from 0 to 30. A separate score for each area (range 0–10) can be calculated. In case an item is scored as unable to perform, the item is given the mean score of the applicable items in the functional area rounded to the nearest integer. No questions regarding aids or devices or need of help from another person are included.

Patient selection.

All patients seen consecutively at the study units between April and September 2005 who had JIA according to International League of Associations for Rheumatology (ILAR) criteria (16) and whose parents/guardians gave informed consent were enrolled in the study. Patients were excluded if they had musculoskeletal abnormalities other than JIA or other diseases that affected functional health status.

Questionnaire completion.

Prior to the study visit, the mother or, if the mother did not attend the clinic, the father of each patient was asked to complete the JAFS and the Italian version of the C-HAQ (17). The 2 questionnaires were presented to the raters in random order, using a computer-generated allocation schedule. The second parent (whenever available) and the patient (if age >8 years) were asked to complete the JAFS independently from each other and from the first parent. In an unselected sample of patients, a fellow (FS or AC-C) completed the JAFS by observing the ability of the child to perform all functions.

The first parent was asked to make a global assessment of the child's well-being on a 10-cm visual analog scale (VAS; 0 = very good, 10 = very poor) and to rate the intensity of the child's pain on a 10-cm VAS (0 = no pain, 10 = very severe pain). The 2 scales were presented on separate forms (18). The same parent was also asked to evaluate the child's health-related quality of life (HRQOL) using the Italian version of the Child Health Questionnaire (CHQ) (17).

Clinical assessments.

At the time of the study visit, the following information was obtained for each patient: sex, age at disease presentation, JIA ILAR category, disease duration, and age at study visit. The following clinical assessments were made by the attending pediatric rheumatologist: physician's global assessment of overall disease activity on a 10-cm VAS (0 = no activity, 10 = maximum activity) and count of joints with swelling, pain/tenderness, functional limitation, and active arthritis. The attending physician also determined functional class according to the Steinbrocker criteria (19). Laboratory assessments included erythrocyte sedimentation rate (ESR) and C-reactive protein level (CRP).

Validation procedures.

To validate the JAFS, we applied the Outcome Measures in Rheumatology Clinical Trials (OMERACT) filter for outcome measures in rheumatology (20, 21). Because our goal was to compare the validity of the JAFS with that of the C-HAQ, most validation procedures were conducted on both instruments. Feasibility or practicality of the JAFS was determined by addressing the issues of brevity, simplicity, and easy scoring, and from the percentage of missing values (22). The time needed to complete the JAFS and the C-HAQ was assessed by timing 42 parents. Parents who completed both questionnaires were asked to indicate the preferred questionnaire. Face and content validity of the JAFS are discussed above.

Criterion validity is a measure of the extent to which values on an instrument agree with those of a gold standard. However, there is no gold standard against which the validity of the JAFS can be tested. For this reason, convergent construct validity was investigated. Construct validity is a form of validation that examines whether the construct in question, in this case the JAFS, is related to other measures in a manner consistent with a priori prediction. Given that the JAFS was devised to measure physical function, we predicted that its correlation with the C-HAQ and with the physical summary score of the CHQ, which measure the same or a very similar construct, would be high. Correlations with the count of limited and painful joints and with the parent's rating of pain were predicted to be moderate, because joint limitation reflects an important component of physical disability, and pain may markedly affect physical function. Correlations with “pure” disease activity parameters, such as physician's global assessment of disease activity, count of swollen joints, ESR, and CRP level, were predicted to be low to moderate. No prediction was attempted regarding correlation with the parent's global assessment because this measure combines the effects of both disease process and functional damage (23), nor with the psychosocial component of HRQOL because it is a multidimensional concept that can be affected by several factors other than functional disability. Correlations were assessed using Spearman's rank correlation. Correlations were considered high if >0.7, moderate if 0.4–0.7, and low if <0.4 (24). Agreement between predicted and observed correlations was considered evidence of construct validity. To determine whether the JAFS exhibited different characteristics in mildly and more severely affected patients, the group of patients with moderate-to-severe disability were identified as those with a C-HAQ score >0.5 (25). Key correlations were then recalculated and compared with those obtained in the entire population.

Discriminating ability was assessed through the one-way analysis of variance by comparing scores from patients with different levels of disability, as measured by Steinbrocker classification (19). Interrater reliability was assessed by calculating the intraclass correlation coefficients (ICCs) (26) between the questionnaires completed by the mother, the father, and the child and the objective evaluation made by the fellow. An ICC value >0.8 was considered indicative of excellent reliability. Internal consistency was determined by calculating the Cronbach's coefficient alpha (27). A value of 0.80 was considered acceptable (28).

The responsiveness to clinical change over time was assessed by asking a parent to complete the questionnaires at the time of a subsequent visit, a mean ± SD of 6 ± 3 months after the first evaluation. At the second visit, the attending physician and the parent were asked to judge for each patient whether the disease was improved, stable, or worsened compared with the baseline visit. Patients whose baseline scores were at the ceiling (score 0) or floor (maximum score) for the questionnaire and could not, therefore, further improve or worsen, respectively, were excluded from the assessment of responsiveness in the group judged as improved or worsened, respectively. Patients who were judged as stable were also excluded. Responsiveness statistics included the standardized response mean (SRM), which was calculated as the mean change in score divided by the SD of individuals' change in score. According to Cohen (29), the threshold levels for the SRM were defined as follows: ≥0.20 = small, ≥0.50 = moderate, and ≥0.80 = good.

All statistical tests were 2-sided and a P value less than 0.05 was considered statistically significant. The Statistica statistical package was used (StatSoft, Tulsa, OK).

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. REFERENCES
  9. APPENDIX A
  10. Supporting Information

Patient characteristics.

A total of 211 patients, whose main demographic and clinical features are presented in Tables 1 and 2, were included in the study. None of the parents/guardians of eligible patients seen in the study period refused participation or were excluded for other reasons.

Table 1. Demographic and clinical features of the 211 study patients*
 No. (%)Mean ± SDMedianRange
  • *

    JIA = juvenile idiopathic arthritis.

Male57 (27)   
Female154 (73)   
Age at onset, years 4.5 ± 3.33.30.6–15.6
JIA category    
 Systemic arthritis15 (7.1)   
 Oligoarthritis persistent93 (44.1)   
 Oligoarthritis extended52 (24.6)   
 Polyarthritis rheumatoid-factor negative36 (17.1)   
 Polyarthritis rheumatoid-factor positive4 (1.9)   
 Psoriatic arthritis5 (2.4)   
 Enthesitis-related arthritis6 (2.8)   
Antinuclear antibody positive159 (75.4)   
Age at study visit, years 8.8 ± 4.58.22.2–18.0
Disease duration, years 4.4 ± 3.43.80.3–17.1
Table 2. Values of juvenile idiopathic arthritis severity measures at study entry*
 Range of possible valuesMean ± SDMedianRange
  • *

    C-HAQ = Childhood Health Assessment Questionnaire; JAFS = Juvenile Arthritis Functionality Scale; CHQ = Child Health Questionnaire; ESR = erythrocyte sedimentation rate.

  • Mean ± SD norm-based score for both physical and psychosocial summary scores 50 ± 1.

Physician's global assessment, cm0–102.7 ± 3.210–10
Parent's global assessment, cm0–102.3 ± 2.610–9.5
Parent's pain assessment, cm0–102.2 ± 2.710–9.7
C-HAQ score0–30.31 ± 0.40.130–1.9
JAFS score0–301.9 ± 2.700–11
JAFS lower limbs score0–101.04 ± 1.800–9
JAFS hand/wrist score0–100.48 ± 1.100–5
JAFS upper segment score0–100.38 ± 0.900–6
Swollen joint count0–602.45 ± 4.210–42
Tender joint count0–672.8 ± 7.100–62
Limited joint count0–652.33 ± 5.300–36
Active joint count0–673.26 ± 610–42
CHQ physical summary score45.6 ± 12.2749.416.4–62.8
CHQ psychosocial summary score48.51 ± 8.2649.418.1–63.3
ESR, mm/hour< 1521.9 ± 20.6141–103
C-reactive protein, mg/dl< 0.31.6 ± 3.60.50.3–29.1

Completion of questionnaires.

A parent (the mother for 190 patients and the father for 21 patients), hereafter referred to as the reference parent, completed both the JAFS and the C-HAQ. The JAFS was also completed independently by 74 fathers who did not serve as the reference parent, and by 92 patients. A fellow, who was blinded to parents' and patients' assessments, completed the JAFS by observing the ability of 121 patients, ages 3.3–18 years, to perform all functions. The scores of questionnaires completed by the reference parent are reported in Table 2. The percentages of patients with a score of 0 for the JAFS and the C-HAQ were 52% and 50%, respectively.

Feasibility.

The JAFS appeared to be easy to complete and score. The mean time for 54 parents to complete the JAFS and the C-HAQ was 1.4 minutes (range 1–4) and 5.3 minutes (range 3–10), respectively. There were no missing responses for the JAFS.

Face and content validity.

As stated above, content validity was established by the members of the group who devised the index and face validity was confirmed by 12 physicians and 4 physiotherapists with specific experience in the field, all of whom agreed. After questionnaire completion, 136 reference parents were asked to indicate their preferred instrument: 89 (65.4%) selected the JAFS, 40 (29.4%) selected the C-HAQ, and 7 (5.2%) judged the 2 questionnaires as equivalent. Reasons for selection of the JAFS included its brevity, simplicity, and forwardness; the C-HAQ was mostly chosen for its greater detail.

Construct validity.

The JAFS was correlated at a high level (rs = 0.73) with the C-HAQ. The Spearman correlation coefficients used to compare the convergent construct validity of the JAFS and the C-HAQ in the entire patient sample and in patients with moderate to severe disability (C-HAQ score >0.5) are shown in Table 3. Most correlations for the JAFS were in the predicted range. All Spearman's correlations yielded by the C-HAQ were lower than those of the JAFS. When the analysis was restricted to patients with greater disability, most correlations for the JAFS increased. It is noteworthy that correlations with the parent's rating of pain, the limited and painful joint counts, and the physical summary score of the CHQ were high (rs > 0.7), which underscores the major impact of pain and restricted joint motion on functional disability and the prominent influence of functional impairment on the physical domain of HRQOL.

Table 3. Comparison of the construct validity of the JAFS and C-HAQ, determined using Spearman's correlation (r) with other quantitative outcome measures*
 JAFSC-HAQ
No.rNo.r
  • *

    See Table 2 for definitions and instrument score ranges.

  • Moderate correlations (r ≥ 0.4 and ≤ 0.7).

  • High correlations (r > 0.7).

Physician's global assessment
 All patients1940.541990.34
 Patients with C-HAQ score >0.5380.52  
Parent's global assessment
 All patients2040.492080.43
 Patients with C-HAQ score >0.5410.59  
Parent's pain assessment
 All patients2050.612090.48
 Patients with C-HAQ score >0.5410.75  
No. of swollen joints
 All patients2030.412080.21
 Patients with C-HAQ score >0.5420.57  
No. of joints with pain on motion/tenderness
 All patients2030.512080.36
 Patients with C-HAQ score >0.5420.70  
No. of joints with restricted motion    
 All patients2030.572080.45
 Patients with C-HAQ score >0.5420.73  
No. of active joints    
 All patients2030.492080.28
 Patients with C-HAQ score >0.5420.64  
CHQ physical summary score
 All patients158−0.58158−0.50
 Patients with C-HAQ score >0.534−0.80  
CHQ psychosocial summary score
 All patients158−0.25158−0.22
 Patients with C-HAQ score >0.534−0.44  
Erythrocyte sedimentation rate
 All patients1580.391620.30
 Patients with C-HAQ score >0.5340.48  
C-reactive protein
 All patients1570.391610.34
 Patients with C-HAQ score >0.5330.51  

Discriminative ability.

The JAFS discriminated well among patients based on Steinbrocker functional class criteria (Figure 1) (19). The discriminative ability of the lower limbs and hand/wrist subscales was comparable with that of the total questionnaire, whereas the upper segment subscale discriminated less well between Steinbrocker disability states. The discriminative ability of the JAFS was comparable with that of the C-HAQ (data not shown).

thumbnail image

Figure 1. Assessment of discriminative ability of the Juvenile Arthritis Functionality Scale (JAFS) in A, lower limbs area, B, hand-wrist area, C, upper segment area, and D, total score based on Steinbrocker functional class criteria (19). The single patient who was in class III was excluded from the analysis; no patient was in class IV. Solid square = mean; shaded square = ± SE; error bars = ± 1.96 SE.

Download figure to PowerPoint

Internal consistency.

Cronbach's alpha for the JAFS was 0.82 for the total score, 0.86 for the lower limb subscale, 0.81 for the hand/wrist subscale, and 0.62 for the upper segment subscale. The lower internal consistency of the upper segment subscales was expected because it includes a more heterogeneous group of functions than do the other subscales.

Interrater reliability.

The level of agreement in JAFS completion among raters, measured through the ICC, is reported in Table 4. There was excellent agreement between mothers and fathers, with an ICC >0.8. Concordance between other raters was satisfactory, with all ICCs ∼0.7. To enable comparison with the ICC yielded by the JAFS, the results obtained with the C-HAQ in our previous analyses (18, 30) are included in Table 4.

Table 4. Comparison of the level of concordance for the JAFS and C-HAQ between mothers, fathers, children, and objective assessment by the external observer*
 JAFSC-HAQ
ChildMotherFatherChildMother
  • *

    Values are the intraclass correlation coefficient (95% confidence interval). See Table 2 for definitions.

  • Data obtained from Garcia-Munitis et al (18).

  • Unpublished data calculated on the original database from Ravelli et al (30).

Mother0.70 (0.57–0.80)  0.44 (0.26–0.59) 
Father0.72 (0.52–0.84)0.84 (0.76–0.89) 0.49 (0.32–0.63)0.80 (0.72–0.87)
Observer0.69 (0.53–0.80)0.71 (0.70–0.80)0.65 (0.47–0.78) 0.47 (0.26–0.63)

Responsiveness.

For 114 patients, the JAFS and the C-HAQ were completed a second time by a parent. The SRM (95% confidence interval [95% CI]) for the JAFS and the C-HAQ was 0.56 (0–1.49) and 0.6 (0.24–0.94), respectively, among patients who were judged as improved by the physicians (n = 20), and 0.55 (0–1.28) and 0.66 (0.35–0.95), respectively, among patients who were judged as improved by the parents (n = 28). Among patients who were judged as worsened by the physicians (n = 26), the SRM (95% CI) for the JAFS and the C-HAQ was 0.42 (0.17–0.68) and 0.15 (0–0.55), respectively, and among those judged as worsened by the parents (n = 21), the SRM (95% CI) was 0.47 (0.18–0.78) and 0.22 (0–0.65), respectively.

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. REFERENCES
  9. APPENDIX A
  10. Supporting Information

We have described the development of a new measure of physical function for children with JIA. It is short and simple, and is quick, taking only 1–2 minutes to complete and score, which makes it practical for use in standard clinical care. The JAFS is proposed for use as both proxy report and patient self-report, with the suggested age range of 8–18 years for use as self-report. The Italian version of the instrument was found to be feasible and to possess face and content validity, good reliability, strong discriminative validity, and fair responsiveness to clinical change over time in a large cohort of patients with JIA. By documenting these key measurement properties, we have demonstrated that the JAFS is a valid tool for the assessment of physical function in this patient population and is, therefore, potentially applicable in both clinical and research settings.

The JAFS differs in many aspects from previous functional scales for JIA. Because we aimed at creating a short questionnaire that could be administered to children of all ages (from 2 to 18 years), we included, for the most part, the basic functions that are relevant to common activities of daily living (ADL), rather than the ADL per se. We assumed that parents or patients are equally able to proxy or self-report, respectively, the patients' ability to perform either the ADL or the simple functions underlying the ADL. Functional activities are grouped into 3 areas, identified by the topography of involved joints or joint groups, which enables an accurate evaluation of the influence of impairment in individual joints on specific functions. This constitutes an advantage over previous questionnaires, which contain many items that assess function of the upper and lower limbs as well as the trunk simultaneously. For example, the lower limbs section of the JAFS may capture functional limitation in a child with oligoarthritis affecting the lower limb joints better than a broad questionnaire. The ease of JAFS tasks permits the verification of proxy or self-reports with the objective assessment of the child's ability in performing the tasks. This property is important because parents' observation of children's physical function has been found to be frequently inaccurate (30). The JAFS is the first functional measure that includes the assessment of the temporomandibular joint, which is frequently involved in patients with JIA (31, 32).

The good psychometric properties of the JAFS were strengthened by the comparison with those of the C-HAQ. In the construct validity analysis, all correlations with the other JIA outcome measures were higher for the JAFS than for the C-HAQ. The concordance between both mother-child, father-child, and mother-father dyads, and between reported scores and observed performance was higher than concordance yielded by the C-HAQ in our previous analyses conducted with a similar design (18, 30) (Table 4). Concerning responsiveness to clinical change over time, the JAFS proved slightly less responsive than the C-HAQ among patients who were judged as improved from baseline to subsequent visit by the physicians or the parents, whereas the JAFS performed better than the C-HAQ among patients who were judged as worsened. The discriminant validity of the 2 questionnaires was similar. Altogether, these findings indicate that the JAFS may be superior to the C-HAQ in terms of construct validity and reliability, and is at least as good as the C-HAQ in terms of discriminant validity and responsiveness to clinical change over time.

Approximately half (52%) of our patients with JIA had a JAFS score of 0, indicating absence of disability. A similar percentage of patients had a normal C-HAQ score (50%). This indicates that the JAFS may not be advantageous over the C-HAQ in terms of ceiling effect (i.e., tendency of scores to cluster at the normal end of the scale). It has been suggested that the ceiling effect makes a functional scale intrinsically less sensitive to milder levels of disability and decreases its ability to detect improvement in function for those patients who are close to or at the ceiling (33, 34). In an attempt to reduce the ceiling effect of the C-HAQ, Lam et al (33) devised 3 modified versions by using new response scales and adding more challenging functions. They found that all new versions of the C-HAQ had less of a ceiling effect and were more normally distributed. However, it has been suggested that if a proportion of patients with chronic arthritis have a functional score of 0, this may not be a ceiling effect. It can instead be interpreted that these patients report no difficulties with any of their ADL, which means that they have no disability (35). In the last decade, a marked decrease in the number of patients with JIA with poor functional outcome has been documented (2, 36, 37). We recently found that 48% of 158 consecutive patients with JIA with a disease duration ≥5 years had a C-HAQ score of 0 (38). A different situation is likely encountered in clinical trials, where only patients with a minimum threshold of disease activity/severity (i.e., at least 5 joints with active arthritis) are enrolled. In 2 recent randomized trials conducted in patients with polyarticular JIA, only 3% (39) and 6% (40) of the patients had a C-HAQ score of 0 at baseline. It should be acknowledged, however, that of the 109 patients who had a JAFS score of 0 in our study, 17.5% had a C-HAQ score >0, 27.2% had ≥1 restricted joint, and 1.9% were in Steinbrocker class II. This means that the function of a number of patients who were scored as having no disability on the JAFS was at least impaired to some extent.

Our study should be viewed in light of certain limitations. Although we present the English translation of the questionnaire (Appendix A), the instrument was validated in Italian patients. It is possible that children and their parents elsewhere might respond differently to the JAFS questionnaire due to cultural and language differences. The low level of disability in most of our patients may have limited the generalizability of our study. However, our patients represent a consecutive sampling of our clinic population and are likely representative of the patients seen in most tertiary pediatric rheumatology centers. Nevertheless, our results should be confirmed at other sites and in different patient settings before the new questionnaire is widely adopted. We acknowledge that our work owes a great deal to previous work on development and validation of functional ability questionnaires for JIA and that some of the items in the tool are the same as or very similar to those in the Juvenile Arthritis Functional Assessment Report (JAFAR) (12) and the C-HAQ (3).

In conclusion, we have developed a new short and simple measure for the assessment of physical function in patients with JIA that is primarily proposed for use in standard clinical care, but may also be applicable in observational studies and randomized trials. This instrument, which was validated in its Italian version, should be further tested in different patient groups and cultural environments.

AUTHOR CONTRIBUTIONS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. REFERENCES
  9. APPENDIX A
  10. Supporting Information

Dr. Ravelli had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study design. Filocamo, Magni-Manzoni, Viola, Ruperto, Buoncompagni, Loy, Martini, Ravelli.

Acquisition of data. Filocamo, Sztajnbok, Cespedes-Cruz, Magni-Manzoni, Viola, Buoncompagni, Loy.

Analysis and interpretation of data. Filocamo, Pistorio, Ruperto, Ravelli.

Manuscript preparation. Martini, Ravelli.

Statistical analysis. Pistorio, Ruperto.

REFERENCES

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. REFERENCES
  9. APPENDIX A
  10. Supporting Information
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    Murray KJ, Passo MH. Functional measures in children with rheumatic diseases [review]. Pediatr Clin North Am 1995; 42: 112753.
  • 2
    Duffy CM. Measurement of health status, functional status, and quality of life in children with juvenile idiopathic arthritis: clinical science for the pediatrician. Pediatr Clin North Am 2005; 52: 35972.
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    Singh G, Athreya BH, Fries JF, Goldsmith DP. Measurement of health status in children with juvenile rheumatoid arthritis. Arthritis Rheum 1994; 37: 17619.
  • 4
    Giannini EH, Ruperto N, Ravelli A, Lovell DJ, Felson DT, Martini A. Preliminary definition of improvement in juvenile arthritis. Arthritis Rheum 1997; 40: 12029.
  • 5
    Ruperto N, Ravelli A, Pistorio A, Malattia C, Cavuto S, Gado-West L, et al. Cross-cultural adaptation and psychometric evaluation of the Childhood Health Assessment Questionnaire (C-HAQ) and the Child Health Questionnaire (CHQ) in 32 countries: review of the general methodology. Clin Exp Rheumatol 2001; 19 Suppl 23: S19.
  • 6
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APPENDIX A

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. REFERENCES
  9. APPENDIX A
  10. Supporting Information
Table  . THE PARENT'S VERSION OF THE JUVENILE ARTHRITIS FUNCTIONALITY SCALE (JAFS)
With this questionnaire, we would like to obtain information on how your child's illness affects his/her physical function. For each question below, please mark the response which best describes your child's ability to perform the task IN THE PAST WEEK. Please indicate only those difficulties or limitations which are CAUSED BY THE DISEASE. If your child has difficulty in doing a certain activity or is unable to do it BECAUSE HE/SHE IS TOO YOUNG but NOT BECAUSE HE/SHE IS LIMITED BY THE DISEASE, please mark it as “Unable to assess”.
Is your child able to:Without any difficultyWith difficultyUnable to doUnable to assess
  1. Items 1–5 constitute the lower limbs area; items 6–10 constitute the hand/wrist area; items 11–15 constitute the upper segment area. The English translation of the Italian version of the questionnaire is presented.

 1. Run on flat ground for at least 10 meters
 2. Walk up five steps
 3. Make a jump forward
 4. Squat down
 5. Bend down to pick up an object from the floor
 6. Carry out activities which involve use of fingers
 7. Clench and unclench the fists
 8. Hold tightly an object with hands
 9. Open a door by lowering the handle
10. Turn on and off water faucets or reopen previously opened jars
11. Extend the arms completely
12. Place hands behind the neck
13. Turn head to look back over shoulders
14. Extend neck to look at ceiling
15. Bite a firm sandwich or an apple

Supporting Information

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. REFERENCES
  9. APPENDIX A
  10. Supporting Information
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