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, drug-related 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].
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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 [8‐10].
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 [12‐14].
14.
Rating of the patient’s overall well-being on a 21-numbered circle VAS.
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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 sub-scales 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.
Results
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.
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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.
In the 100 JIA subjects, the JIA categories were 7.0% with systemic arthritis, 38.0% with oligoarthritis, 27.0% with RF negative polyarthritis, 1.0% with RF positive polyarthritis, 5.0% with psoriatic arthritis, 9.0% with Enthesitis related arthritis and 13.0% with undifferentiated arthritis (Table 1).
Table 1
Descriptive statistics (medians, 1st 3rd quartiles or absolute frequencies and %) for the 100 JIA patients
Systemic (N = 7) | Oligoarthritis (N = 38) | RF− poly-arthritis (N = 27) | RF+ poly-arthritis (N = 1) | Psoriatic arthritis (N = 5) | Enthesitis related arthritis (N = 9) | Undifferentiated arthritis (N = 13) | All JIA patients (N = 100) | Healthy (N = 100) | |
|---|---|---|---|---|---|---|---|---|---|
Female | 4 (57.1%) | 23 (60.5%) | 22 (81.5%) | 1 (100%) | 3 (60%) | 4 (44.4%) | 8 (61.5%) | 65 (65%) | 53 (53%) |
Age at visit | 11.9 (6.8–12.9) | 9.9 (5-12.8) | 11.9 (9.9–15.8) | 17.9 (17.9–17.9) | 12.8 (11.9–13.9) | 14.9 (10-15.8) | 11.9 (10.8–12.9) | 11.8 (8.8–14.4)* | 9.8 (6.1–14)* |
Age at onset | 7.1 (1.4–8.9) | 3.2 (2.3–6.8) | 5.8 (2.6–9.3) | 13.2 (13.2–13.2) | 9.8 (3.4–10.5) | 9 (8.3–11.1) | 4 (2-6.5) | 5.6 (2.4-9)* | |
Disease duration | 4.8 (3.1–5.5) | 3.3 (1.3-7) | 5.1 (2-9.5) | 4.7 (4.7–4.7) | 3.5 (2.9–7.5) | 3.7 (1.7–4.9) | 6.3 (3.2–9.3) | 4.6 (1.8–7.6) | |
ESR | 5 (1–5) | 8 (5–12) | 8 (5–12) | 6 (6–6) | 12 (10–14) | 8 (8–9) | 6 (4–15) | 8 (5–12) | |
MD VAS (0–10 cm) | 0 (0–1) | 0 (0–2) | 1 (0–2) | 0 (0–0) | 0 (0–0) | 1 (0–2) | 0 (0–2) | 0 (0–2) | |
No. swollen joints | 0 (0–0) | 0 (0–1) | 0 (0–2) | 0 (0–0) | 0 (0–0) | 1 (0–2) | 0 (0–0) | 0 (0–1) | |
No. joints with pain | 0 (0–0) | 0 (0–1) | 0 (0–2) | 0 (0–0) | 0 (0–0) | 0 (0–2) | 0 (0–1) | 0 (0–1) | |
No. joints with LOM | 0 (0–1) | 1 (0–2) | 1 (0–3) | 1 (1–1) | 0 (0–1) | 2 (0–4) | 2 (0–4) | 1 (0–3) | |
No. active joints | 0 (0–0) | 0 (0–1) | 1 (0–2) | 0 (0–0) | 0 (0–0) | 1 (0–3) | 0 (0–1) | 0 (0-1.5) | |
Active systemic features | 2 (28.6%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 2 (2%) | |
ANA status | 0 (0%) | 3 (7.9%) | 7 (25.9%) | 0 (0%) | 0 (0%) | 0 (0%) | 1 (7.7%) | 11 (11%) | |
Uveitis | 0 (0%) | 7/37 (18.9%) | 5 (18.5%) | 0 (0%) | 1 (20%) | 0 (0%) | 1 (7.7%) | 14 (14.1%) | |
PF total score | 1 (0–4) | 1 (0–5) | 3 (1–6) | 2 (2–6) | 5 (2–11) | 2 (0–3) | 2 (0–5)* | 0 (0–0)# | |
Pain VAS | 0.5 (0-3.5) | 1.8 (0-3.5) | 2.5 (0.5–5.5) | 5.5 (0–7) | 4 (3–7) | 1.5 (0–4) | 2.5 (0.5-5) | 0 (0–0)# | |
Disease activity VAS | 1.5 (0–3) | 2 (0–4) | 2.5 (0.5-5) | 5 (0-5.5) | 6 (3.5–6.5) | 1.5 (0–7) | 2 (0–5) | ||
Well-being VAS | 1.5 (0-3.5) | 1 (0–3) | 3 (1–5) | 3 (0–7) | 3 (1–7) | 0.5 (0–4) | 1.5 (0–5) | ||
HRQoL PhH | 1 (1–4) | 3 (0–5) | 5 (3–7) | 4 (4–6) | 5 (4–8) | 2 (1–4) | 4 (1–6)* | 0 (0–0)# | |
HRQoL PsH | 3 (0–3) | 1 (0–4) | 3 (2–5) | 1 (0–5) | 3 (2–4) | 2 (0–2) | 2 (0–4) | 0 (0–0)# | |
HRQoL total score | 4 (1–10) | 4 (1–10) | 8 (6–11) | 5 (4–11) | 9 (5–10) | 4 (1–7) | 6 (2–10) | 0 (0–1)# | |
Pain/swell. in > 1 joint | 2 (28.6%) | 22 (57.9%) | 16/25 (64%) | 3 (60%) | 8 (88.9%) | 8 (61.5%) | 59/97 (60.8%) | 4 (5%)# | |
Morning stiffness > 15 min | 3 (42.9%) | 14 (36.8%) | 16/25 (64%) | 3 (60%) | 6 (66.7%) | 2 (15.4%) | 44/97 (45.4%) | 0 (0%)# | |
Subjective remission | 4 (57.1%) | 25 (65.8%) | 19/25 (76%) | 3 (60%) | 8 (88.9%) | 8 (61.5%) | 67/97 (69.1%) | ||
In treatment | 7 (100%) | 25 (65.8%) | 24/25 (96%) | 5 (100%) | 7 (77.8%) | 9 (69.2%) | 77/97 (79.4%) | ||
Reporting side effects | 3/7 (42.9%) | 5/25 (20%) | 15/25 (62.5%) | 4 (80%) | 4/7 (57.1%) | 3/9 (33.3%) | 34/77 (44.2%) | ||
Taking medication regularly | 6/7 (85.7%) | 24/25 (96%) | 21/24 (87.5%) | 5 (100%) | 6/7 (85.7%) | 8/9 (88.9%) | 70/77 (90.9%) | ||
With problems attending school | 2/4 (50%) | 4/18 (22.2%) | 10/19 (52.6%) | 1/2 (50%) | 2/6 (33.3%) | 2/7 (28.6%) | 21 (37.5%) | 0 (0%)# | |
Satisfied with disease outcome | 7 (100%) | 27 (71.1%) | 19/25 (76%) | 5 (100%) | 4 (44.4%) | 9 (69.2%) | 71/97 (73.2%) |
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.
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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.
Table 2
Main psychometric characteristics between the parent and child version of the JAMAR
Parent (N = 97/177) | Child (N = 71/112) | |
|---|---|---|
Missing values (1st–3rd quartiles) | No missing values | No missing values |
Response pattern | PF and HRQoL positively skewed | PF and HRQoL positively skewed |
Floor effect, median | ||
PF | 79.0% | 56.0% |
HRQoL PhH | 44.0% | 30.0% |
HRQoL PsH | 54.0% | 41.0% |
Pain VAS | 24.0% | 13.0% |
Disease activity VAS | 27.0% | 11.0% |
Well-being VAS | 31.0% | 17.0% |
Ceiling effect, median | ||
PF | 0.0% | 0.0% |
HRQoL PhH | 5.0% | 2.0% |
HRQoL PsH | 1.0% | 2.0% |
Pain VAS | 0.0% | 1.0% |
Disease activity VAS | 0.0% | 0.0% |
Well-being VAS | 0.0% | 1.0% |
Items with equivalent item-scale correlation | 87% for PF, 90% for HRQoL | 87% for PF, 80% for HRQoL |
Items with items-scale correlation ≥ 0.4 | 100% for PF, 100% for HRQoL | 93% for PF, 100% for HRQoL |
Cronbach’s alpha | ||
PF-LL | 0.87 | 0.86 |
PF-HW | 0.85 | 0.85 |
PF-US | 0.82 | 0.74 |
HRQoL-PhH | 0.88 | 0.86 |
HRQoL-PsH | 0.82 | 0.81 |
Items with item-scale correlation lower than the Cronbach alpha | 100% for PF, 100% for HRQoL | 100% for PF, 100% for HRQoL |
Test–retest intraclass correlation | ||
PF total score | 0.95 | 0.97 |
HRQoL-PhH | 0.91 | 0.92 |
HRQoL-PsH | 0.99 | 0.88 |
Spearman’s correlation with JIA core-set variables, median | ||
PF | 0.4 | 0.3 |
HRQoL PhH | 0.5 | 0.4 |
HRQoL PsH | 0.3 | 0.2 |
Pain VAS | 0.4 | 0.5 |
Disease activity VAS | 0.4 | 0.4 |
Well-being VAS | 0.4 | 0.5 |
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Descriptive statistics (first Likert assumption)
There were no missing results for all JAMAR items, since data were collected through a web-based system that did not allow to skip answers and input of null values. The response pattern for both PF and HRQoL was positively skewed toward normal functional ability and normal HRQoL. All response choices were used for the different HRQoL items, whereas a reduced number of response choices was used for all the PF items except for items 1, 2, 3, 4 and 5.
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.
Floor and ceiling effect
The median floor effect was 79.0% (69.0–87.0%) for the PF items, 44.0% (32.0–48.0%) for the HRQoL PhH items, and 54.0% (51.0–55.0%) for the HRQoL PsH items. The median ceiling effect was 0% (0–1.0%) for the PF items, 5.0% (0–5.0%) for the HRQoL PhH items, and 1.0% (1–2.0%) for the HRQoL PsH items. The median floor effect was 24.0% for the pain VAS, 27.0% for the disease activity VAS and 31.0% for the well-being VAS. The median ceiling effect was 0% for the pain VAS, 0% for the disease activity VAS and 0% for the well-being VAS.
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.
Cronbach’s alpha internal consistency
Cronbach’s alpha was 0.87 for PF-LL, 0.85 for PF-HW, 0.82 for PF-US. Cronbach’s alpha was 0.88 for HRQoL-PhH and 0.82 for HRQoL-PsH.
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 cross-culturally 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.
Acknowledgements
We thank all families who participated in the project, the team that prepared and reviewed the forward and backward translations, and all members of PRINTO in United Kingdom. We thank the staff of the PRINTO International Coordinating Centre in Genoa (Italy) and in particular Marco Garrone for the overall coordination of the translation process, Silvia Scala and Elisa Patrone for data collection and quality assurance, Luca Villa, Giuseppe Silvestri and Mariangela Rinaldi for the database development and management and the remaining PRINTO team for data entry. The Principal Investigator of the study was Prof. Angelo Ravelli, MD. The scientific coordinator and study methodologist was Nicolino Ruperto, MD, MPH. The project coordinators were Alessandro Consolaro, MD, PhD, Francesca Bovis, BsA. We also thank Prof. Alberto Martini, PRINTO Chairman. Funding was provided by the Istituto G. Gaslini, Genoa (Italy). Permission for the use of JAMAR and its translations must be obtained in writing from PRINTO, Genoa, Italy. All JAMAR-related inquiries should be directed to at printo@gaslini.org. Permission for the use of CHAQ and CHQ derived-material is granted through the scientific cooperation of the copyright holder ICORE of Woodside CA and HealthActCHQ Inc. of Boston, Massachusetts USA. All CHQ-related inquiries should be directed to licensing@healthactchq.com. All CHAQ-related inquiries should be directed to gsingh@stanford.edu.
Compliance with ethical standards
Conflict of interest
Dr. Anderson, Dr. Davidson and Dr. Martin report funding support from Istituto Giannina Gaslini, Genoa, Italy, for the translation and data collection performed at their sites within the EPOCA project. Dr. Ruperto has received Grants from BMS, Hoffman-La Roche, Janssen, Novartis, Pfizer, Sobi, during the conduct of the study and personal fees and speaker honorarium from Abbvie, Ablynx, Amgen, AstraZeneca, Baxalta Biosimilars, Biogen Idec, Boehringer, Bristol Myers Squibb, Celgene, Eli-Lilly, EMD Serono, Gilead Sciences, Janssen, Medimmune, Novartis, Pfizer, Rpharm, Roche, Sanofi, Servier and Takeda. Dr. Consolaro and Dr. Bovis have nothing to disclose.
Ethical approval
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Informed consent
Informed consent was obtained from all individual participants included in the study as per the requirement of the local ethical committee.
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