The British English version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR)

The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient-reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the British English language. The reading comprehension of the questionnaire was tested in ten JIA parents and patients. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the three Likert assumptions, floor/ceiling effects, internal consistency, Cronbach’s alpha, interscale correlations, test–retest reliability, and construct validity (convergent and discriminant validity). A total of 100 JIA patients (7.0% systemic, 38.0% oligoarticular, 27.0% RF negative polyarthritis, 28% other categories) and 100 healthy children, were enrolled at the Royal Hospital for Sick Children in Glasgow. The JAMAR components discriminated well healthy subjects from JIA patients. All JAMAR components revealed good psychometric performances. In conclusion, the British English version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practice and clinical research.


Introduction
The aim of the present study was to cross-culturally adapt and validate the British English parent, child/adult version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR) [1] in patients with juvenile idiopathic arthritis (JIA). The JAMAR assesses the most relevant parent/patient-reported outcomes in JIA, including overall well-being, functional status, health-related quality of life (HRQoL), pain, morning stiffness, disease activity/status/ course, articular and extra-articular involvement, drugrelated side effects/compliance and satisfaction with illness outcome.
This project was part of a larger multinational study conducted by the Paediatric Rheumatology International Trials Organisation (PRINTO) [2] aimed to evaluate the Epidemiology, Outcome and Treatment of Childhood Arthritis (EPOCA) in different geographic areas [3].
We report herein the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the British English language.

Materials and methods
The methodology employed has been described in detail in the introductory paper of the supplement [4]. In brief, it was a cross-sectional study of JIA children, classified according to the ILAR criteria [5,6] and enrolled from February 2013 to July 2013. Children were recruited after Ethics Committee approval and consent from at least one parent.

The JAMAR
The JAMAR [1] includes the following 15 sections: 1. Assessment of physical function (PF) using 15-items in which the ability of the child to perform each task is scored as follows: 0 = without difficulty, 1 = with some difficulty, 2 = with much difficulty, 3 = unable to do and not applicable if it was not possible to answer the question or the patient was unable to perform the task due to their young age or to reasons other than JIA. The total PF score ranges from 0 to 45 and has 3 components: PF-lower limbs (PF-LL); PF-hand and wrist (PF-HW) and PF-upper segment (PF-US) each scoring from 0 to 15 [7]. Higher scores indicating higher degree of disability [8][9][10]. 2. Rating of the intensity of the patient's pain on a 21-numbered circle Visual Analogue Scale (VAS) [11]. 3. Assessment of the presence of joint pain or swelling (present/absent for each joint). 4. Assessment of morning stiffness (present/absent). 5. Assessment of extra-articular symptoms (fever and rash) (present/absent). 6. Rating of the level of disease activity on a 21-circle VAS. 7. Rating of disease status at the time of the visit (categorical scale).
8. Rating of disease course from previous visit (categorical scale). 9. Checklist of the medications the patient is taking (list of choices). 10. Checklist of side effects of medications. 11. Report of difficulties with medication administration (list of items). 12. Report of school/university/work problems caused by the disease (list of items). 13. Assessment of HRQoL, through the Physical Health (PhH), and Psychosocial Health (PsH) subscales (five items each) and a total score. The four-point Likert response, referring to the prior month, are 'never' (score = 0), 'sometimes' (score = 1), 'most of the time' (score = 2) and 'all the time' (score = 3). A 'not assessable' column was included in the parent version of the questionnaire to designate questions that cannot be answered because of developmental immaturity. The total HRQoL score ranges from 0 to 30, with higher scores indicating worse HRQoL. A separate score for PhH and PsH (range 0-15) can be calculated [12][13][14]. 14. Rating of the patient's overall well-being on a 21-numbered circle VAS. 15. A question about satisfaction with the outcome of the illness (yes/no) [15].
The JAMAR is available in three versions, one for parent proxy-report (child's age 2-18), one for child self-report, with the suggested age range of 7-18 years, and one for adults.

Cross-cultural adaptation and validation
The standard English version of JAMAR was defined in occasion of three different consensus meetings where three independent professional translators agreed on a unique standard English translation of the first Italian draft of JAMAR. The three independent translators were selected on the basis of their native language, their age and sex. This standard English version was spread out through the PRINTO national coordinators who had agreed to participate. Reading comprehension and understanding of the text was tested in a probe sample of ten JIA parents and ten patients.
Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents.
The statistical validation phase explored the descriptive statistics and the psychometric issues [16]. In particular, we evaluated the following validity components: the first Likert assumption [mean and standard deviation (SD) equivalence]; the second Likert assumption or equal items-scale correlations (Pearson r: all items within a scale should contribute equally to the total score); third Likert assumption (item internal consistency or linearity for which each item of a scale should be linearly related to the total score that is 90% of the items should have Pearson r ≥ 0.4); floor/ceiling effects (frequency of items at lower and higher extremes of the scales, respectively); internal consistency, measured by the Cronbach's alpha, interscale correlation (the correlation between two scales should be lower than their reliability coefficients, as measured by Cronbach's alpha); test-retest reliability or intra-class correlation coefficient (reproducibility of the JAMAR repeated after 1 or 2 weeks); and construct validity in its two components: the convergent or external validity which examines the correlation of the JAMAR subscales with the six JIA core set variables, with the addition of the parent assessment of disease activity and pain by the Spearman's correlation coefficients (r) [17] and the discriminant validity, which assesses whether the JAMAR discriminates between the different JIA categories and healthy children [18].
Quantitative data were reported as medians with 1st and 3rd quartiles and categorical data as absolute frequencies and percentages.
The complete British English parent and patient versions of the JAMAR are available upon request to PRINTO.

Cross-cultural adaptation
In the probe technique analysis, all 123 lines were understood by at least 80% of the parents (median 100%; range 90-100%). All the 120 lines of the patient version of the JAMAR were understood by at least 80% of the children (median 100%; range 90-100%). The texts of the parent JAMAR and of the child JAMAR were unmodified after the probe technique.

Probe technique
In the probe technique analysis, all the 123 lines of the parent version of the JAMAR were understood by at least 80% of the 10 parents tested (median 100%; range 90-100%). For the 120 lines of the patient version of the JAMAR, all the lines were understood by at least 80% of the children (median 100%; range 90-100%). The texts of the parent JAMAR and of the child JAMAR were unmodified after the probe technique.

Demographic and clinical characteristics of the subjects
A total of 100 JIA patients and 100 healthy children (total of 200 subjects), were enrolled at the Royal Hospital for Sick Children in Glasgow.
A total of 177/200 (88.5%) subjects had the parent version of the JAMAR completed by a parent (97 from parents of JIA patients and 80 from parents of healthy children). The JAMAR was completed by 133/177 (75.1%) mothers and 44/177 (24.9%) fathers. The child version of the JAMAR was completed by 112/200 (56.0%) children age 6.7 or older. Also patients younger than 7 years old, capable to assess their personal condition and able to read and write, were asked to fill in the patient version of the questionnaire.

Discriminant validity
The JAMAR results are presented in Table 1, including the scores [median (1st-3rd quartile)] obtained for the PF, the PhH, the PsH subscales and total score of the HRQoL scales. The JAMAR components discriminated well between healthy subjects and JIA patients.
In summary, the JAMAR revealed that JIA patients had a greater level of disability and pain, as well as a lower HRQoL than their healthy peers.

Psychometric issues
The main psychometric properties of both parent and child versions of the JAMAR are reported in Table 2. The following results section refers mainly to the parent's version findings, unless otherwise specified.
The mean and SD of the items within a scale were roughly equivalent for the PF and for the HRQoL items, except for HRQoL items 1 and 8 (data not shown). The median number of items marked as not applicable was 0% (0-0%) for the PF and 1% (0-3%) for the HRQoL.

Equal items-scale correlations (second Likert assumption)
Pearson items-scale correlations corrected for overlap were roughly equivalent for items within a scale for 87% of the PF items, with the exception of PF items 11 and 15, and for 90% of the HRQoL items, with the exception of item 1.

Items internal consistency (third Likert assumption)
Pearson items-scale correlations were ≥ 0.4 for 100% of items of the PF and 100% of items of the HRQoL.

Interscale correlation
The Pearson correlation of each item of the PF and the HRQoL with all items included in the remaining scales of the questionnaires was lower than the Cronbach's alpha.

Test-retest reliability
Reliability was assessed in eight JIA patients, by re-administering both versions (parent and child) of the JAMAR after a median of 7 days (7-7 days). The intraclass correlation coefficients (ICC) for the PF total score showed an almost perfect reproducibility (ICC 0.95). The ICC for the HRQoL PhH and for the HRQoL PsH scores showed an almost perfect reproducibility (ICC 0.91 and 0.99, respectively).

Convergent validity
The Spearman's correlation of the PF total score with the JIA core set of outcome variables ranged from 0.3 to 0.7 (median 0.4). The PF total score best correlation was observed with the parent assessment of pain (r = 0.7, p < 0.001). For the HRQoL, the median correlation of the PhH with the JIA core set of outcome variables ranged from 0.3 to 0.7 (median 0.5), whereas for the PsH ranged from 0.2 to 0.6 (median 0.3). The PhH showed the best correlation with the parent's assessment of pain (r = 0.8, p < 0.001) and the PsH with the parent global assessment of well-being (r = 0.7, p < 0.001). The median correlations between the pain VAS, the well-being VAS, and the disease activity VAS and the physician-centred and laboratory measures were 0.4 (range 0.3-0.5).

Discussion
The British English version of the JAMAR was crossculturally adapted from the original standard English version, without performing the forward and backward translations. The PRINTO National Coordinator in UK revised the standard English original, adapted it to British English and administered it to a probe sample of ten JIA parents and ten patients. According to the results of the validation analysis, the British English parent and patient versions of the JAMAR possess satisfactory psychometric properties. The disease-specific components of the questionnaire discriminated well between patients with JIA and healthy controls. The PF total score and the PhH score proved to discriminate between the different JIA subtypes with children with Enthesitis related arthritis having a higher degree of disability and a lower quality of life. Psychometric performances were good for all domains of the JAMAR and the overall internal consistency was good for all the domains.
In the external validity evaluation, the Spearman's correlations of the PF and HRQoL scores with JIA core set parameters ranged from weak to moderate.
The statistical performances of the child version of the JAMAR are very similar, although slightly poorer, to those obtained by the parent version, which suggests that children are reliable reporters of their disease and health status.
The JAMAR is aimed to evaluate the side effects of medications and school attendance, which are other dimensions of daily life than most of the previously used HRQoL-tools. This may provide useful information for intervention and follow-up in health care.
In conclusion, the British English version of the JAMAR was found to have excellent psychometric properties and it is, thus, a reliable and valid tool for the multidimensional assessment of children with JIA.