Introduction
The aim of the present study was to cross-culturally adapt and validate the Turkish 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 Turkish 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 July 2012 to October 2014. 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 three 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) sub-scales (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 process of cross-cultural adaptation was conducted according to international guidelines with 2–3 forward and backward translations. In those countries for which the translation of JAMAR had been already cross-cultural adapted in a similar language (i.e., Spanish in South American countries), only the probe technique was performed. Reading comprehension and understanding of the translated questionnaires were 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 item-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 6 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 first and third quartiles and categorical data as absolute frequencies and percentages.
The complete Turkish parent and patient versions of the JAMAR are available upon request to PRINTO.
Results
Cross-cultural adaptation
The Turkish JAMAR was fully cross-culturally adapted from the standard English version with three forward and two backward translations with concordance in 119/123 translation lines (96.7%) for the parent version and 107/120 lines (89.2%) for the child version.
Of the 123 lines in the parent version of the JAMAR, 118 (96%) were understood by at least 80% of the 10 parents tested (median = 100%; range: 20–100%); 114/120 (95%) lines of the patient version of the JAMAR were understood by at least 80% of the children (median = 100%; range: 70–100%). Lines 10, 55, 57, 113, and 114 of parent version of the Turkish JAMAR and lines 9, 51, 53, 55, 107, and 110 of the child version were modified according to parents/children suggestions after the probe technique.
Demographic and clinical characteristics of the subjects
A total of 468 JIA patients and 95 healthy children (total of 563 subjects) were enrolled at five paediatric rheumatology centres. Two patients and two healthy children did not give the consent to use their data.
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In the remaining 466 JIA subjects, the JIA categories were 13.7% with systemic arthritis, 40.6% with oligoarthritis, 22.5% with RF negative poly-arthritis, 2.4% with RF positive poly-arthritis, 3.2% with psoriatic arthritis, 15% with enthesitis related arthritis, and 2.6% with undifferentiated arthritis (Table 1).
Table 1
Descriptive statistics (medians, first–third quartiles or absolute frequencies and %) for the 466 JIA patients
Systemic | Oligoarthritis | RF − poly-arthritis | RF + poly-arthritis | Psoriatic Arthritis | Enthesitis related arthritis | Undifferentiated arthritis | All JIA patients | Healthy | |
|---|---|---|---|---|---|---|---|---|---|
N = 64 | N = 189 | N = 105 | N = 11 | N = 15 | N = 70 | N = 12 | N = 466 | N = 93 | |
Female | 35 (54.7%) | 133 (70.4%) | 73 (69.5%) | 9 (81.8%) | 7 (46.7%) | 11 (15.7%) | 11 (91.7%) | 279 (59.9%)# | 49 (52.7%) |
Age at visit | 10 (7.2–13.3) | 7.3 (5–11) | 11.3 (7.6–14.5) | 14.9 (14.4–15.8) | 13.3 (10.3–15) | 14.5 (12.2–16.5) | 15.9 (15.4–16.4) | 10.8 (6.6–14.3)# | 11.9 (9.6–13.4)* |
Age at onset | 5.8 (2.4–8.9) | 3.8 (1.7–7.3) | 6.8 (3.8–10.8) | 9.5 (7.8–13.2) | 5.8 (3.2–11.4) | 11.8 (9.3–13.6) | 13.9 (12.8–14.4) | 6.3 (2.7–10.8)# | |
Disease duration | 2.9 (1.1–6.2) | 2.3 (1-4.2) | 2.9 (1.5–5.4) | 4.1 (1.1–6.7) | 4.8 (2.8–8.6) | 2.4 (1.2–4.1) | 1.9 (1.1-3) | 2.6 (1.2–4.6)* | |
ESR | 12 (9–30) | 14 (8–24) | 15 (10–26) | 24 (19–46) | 12 (9–16) | 12 (6–22) | 13 (10–33) | 14 (8–25) | |
MD VAS (0–10 cm) | 1 (0-2.5) | 1.5 (0.5-4) | 3.5 (1–5) | 2.5 (2–6) | 1 (0–3) | 2 (1–4) | 3.8 (3-5.3) | 2 (0.5-4)# | |
No. swollen joints | 0 (0–0) | 0 (0–1) | 0 (0–3) | 1 (0–6) | 0 (0–1) | 0 (0–0) | 0 (0–0) | 0 (0–1)# | |
No. joints with pain | 0 (0–0) | 0 (0–1) | 1 (0–4) | 2 (0–13) | 0 (0–0) | 0 (0–3) | 2 (0.5-4) | 0 (0–2)# | |
No. joints with LOM | 0 (0–1) | 0 (0–1) | 1 (0–2) | 1 (0–2) | 0 (0–0) | 0 (0–1) | 0 (0-0.5) | 0 (0–1)# | |
No. active joints | 0 (0–1) | 1 (0–1) | 1 (0–4) | 2 (0–6) | 0 (0–1) | 0 (0–1) | 0 (0-0.5) | 0 (0–2)# | |
Active systemic features | 9 (14.1%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 9 (2%)# | |
ANA status | 0 (0%) | 33 (17.5%) | 10 (9.5%) | 2 (18.2%) | 1 (6.7%) | 0 (0%) | 0 (0%) | 46 (9.9%)# | |
Uveitis | 0 (0%) | 25 (13.4%) | 8 (7.9%) | 0 (0%) | 0 (0%) | 4 (5.9%) | 0 (0%) | 37 (8.1%)* | |
PF Total Score | 1 (0-4.5) | 1 (0–3) | 3 (0–9) | 3 (2–10) | 0 (0–4) | 1 (0–4) | 2.5 (1.5–14) | 2 (0–5)** | 0 (0–1)# |
Pain VAS | 0 (0-3.3) | 1 (0–3) | 2 (0-4.5) | 2 (0–5) | 0 (0-3.5) | 1 (0-4.8) | 4.5 (2.5–8.5) | 1 (0–4)* | 0 (0–0)# |
Disease activity VAS | 0 (0-2.5) | 1 (0–3) | 1.5 (0–4) | 3.8 (0.5-5) | 0.5 (0-2.5) | 1 (0-3.5) | 3.3 (2.8-6) | 1 (0-3.5)* | |
Well-being VAS | 1 (0-2.5) | 1 (0–4) | 2 (0–5) | 5 (1.5–6.5) | 1 (0–5) | 1 (0-4.5) | 4.3 (2.5–6.5) | 1 (0-4.5)* | |
HRQoL-PhH | 1 (0–4) | 3 (0–5) | 2 (1–5) | 5 (1–5) | 1 (0–4) | 2 (0–4) | 4 (1.5–8.5) | 2 (0–5)* | 0 (0–3)# |
HRQoL-PsH | 3 (1–5) | 2 (0–4) | 3 (1–5) | 3 (1–8) | 3 (0–6) | 2 (0–5) | 4 (2-6.5) | 2 (1–5) | 1.5 (0–3)** |
HRQoL total score | 4 (2–9) | 5 (2–9) | 6 (2–10) | 7 (6–13) | 6 (1–8) | 4.5 (1–9) | 9 (5.5–12) | 5 (2–10) | 2 (0–6)# |
Pain/swell. in > 1 joint | 25 (39.1%) | 118/188 (62.8%) | 74/103 (71.8%) | 8 (72.7%) | 7 (46.7%) | 38 (54.3%) | 12 (100%) | 282/463 (60.9%)# | 5/92 (5.4%)# |
Morning stiffness > 15 min | 10 (15.6%) | 29/185 (15.7%) | 27/96 (28.1%) | 3/10 (30%) | 3/14 (21.4%) | 15/69 (21.7%) | 4 (33.3%) | 91/450 (20.2%) | 2/90 (2.2%)# |
Subjective remission | 23/63 (36.5%) | 109/177 (61.6%) | 72/93 (77.4%) | 7/10 (70%) | 9/14 (64.3%) | 38/65 (58.5%) | 10 (83.3%) | 268/434 (61.8%)# | |
In treatment | 48/63 (76.2%) | 168/185 (90.8%) | 89/101 (88.1%) | 11 (100%) | 13/14 (92.9%) | 61/67 (91%) | 11 (91.7%) | 401/453 (88.5%) | |
Reporting side effects | 22/48 (45.8%) | 56/162 (34.6%) | 38/86 (44.2%) | 3 (27.3%) | 5/12 (41.7%) | 24/61 (39.3%) | 6/10 (60%) | 154/390 (39.5%) | |
Taking medication regularly | 41/47 (87.2%) | 151/163 (92.6%) | 80/87 (92%) | 11 (100%) | 10/13 (76.9%) | 55/61 (90.2%) | 8/11 (72.7%) | 356/393 (90.6%) | |
With problems attending school | 7/32 (21.9%) | 19/95 (20%) | 15/56 (26.8%) | 1/3 (33.3%) | 2/6 (33.3%) | 14/47 (29.8%) | 4/8 (50%) | 62/247 (25.1%) | 3/81 (3.7%)# |
Satisfied with disease outcome | 34/61 (55.7%) | 73/180 (40.6%) | 38/97 (39.2%) | 4/10 (40%) | 11 (73.3%) | 31/64 (48.4%) | 3 (25%) | 194/439 (44.2%) |
A total of 555/559 (99.3%) subjects had the parent version of the JAMAR completed by a parent (463 from parents of JIA patients and 92 from parents of healthy children). The JAMAR was completed by 364/555 (65.6%) mothers and 191/555 (34.4%) fathers. The child version of the JAMAR was completed by 438/555 (78.9%) children age 6 or older. In addition, patients younger than 7 years, 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 sub-scales, and total score of the HRQoL scales. The JAMAR components discriminated well between healthy subjects and JIA patients.
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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 versions of the JAMAR
Parent N = 463/555 | Child N = 348/438 | |
|---|---|---|
Missing values (1st–3rd quartiles) | 2.3% (1.1–3.1%) | 1.9% (0.4–2.6%) |
Response pattern | PF and HRQoL positively skewed | PF and HRQoL positively skewed |
Floor effect, median | ||
PF | 83.2% | 85.1% |
HRQoL PhH | 49.7% | 54.0% |
HRQoL-PsH | 49.9% | 60.1% |
Pain VAS | 39.5% | 34.2% |
Disease activity VAS | 35.6% | 36.2% |
Well-being VAS | 33.0% | 34.5% |
Ceiling effect, median | ||
PF | 1.3% | 0.9% |
HRQoL PhH | 3.0% | 4.0% |
HRQoL-PsH | 2.6% | 2.0% |
Pain VAS | 2.2% | 1.1% |
Disease activity VAS | 1.9% | 0.6% |
Well-being VAS | 1.5% | 0.6% |
Items with equivalent item-scale correlation | 93% for PF, 100% for HRQoL | 100% for PF, 100% for HRQoL |
Items with item-scale correlation ≥ 0.4 | 100% for PF, 100% for HRQoL | 100% for PF,100% for HRQoL |
Cronbach’s alpha | ||
PF–LL | 0.87 | 0.85 |
PF–HW | 0.90 | 0.88 |
PF–US | 0.84 | 0.79 |
HRQoL–PhH | 0.87 | 0.88 |
HRQoL–PsH | 0.82 | 0.78 |
Items with item-scale correlation lower than the Cronbach alpha | 100% for PF, 100% for HRQoL | 100% for PF, 100% for HRQoL |
Test–retest intra-class correlation | ||
PF total score | 0.96 | 0.83 |
HRQoL–PhH | 0.78 | 0.94 |
HRQoL–PsH | 0.86 | 0.77 |
Spearman correlation with JIA core-set variables, median | ||
PF | 0.5 | 0.5 |
HRQoL PhH | 0.5 | 0.5 |
HRQoL-PsH | 0.3 | 0.3 |
Pain VAS | 0.4 | 0.4 |
Disease activity VAS | 0.4 | 0.4 |
Well-being VAS | 0.4 | 0.4 |
Descriptive statistics (first Likert assumption)
For all JAMAR items, the median number of missing responses was 2.3% (1.1–3.1%).
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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 were used for the PF item 15.
The mean and SD of the items within a scale were roughly equivalent for the PF and for the HRQoL items (data not shown). The median number of items marked as not applicable was 1% (1–4%) for the PF and 8.5% (5–14%) for the HRQoL.
Floor and ceiling effect
The median floor effect was 83.2% (73.2–89.4%) for the PF items, 49.7% (42.8–53.1%) for the HRQoL PhH items, and 49.9% (39.7–62.2%) for the HRQoL-PsH items. The median ceiling effect was 1.3% (0.6–1.7%) for the PF items, 3.0% (3.0-4.3%) for the HRQoL PhH items, and 2.6% (2.2–4.8%) for the HRQoL-PsH items. The median floor effect was 39.5% for the pain VAS, 35.6% for the disease activity VAS, and 33% for the well-being VAS. The median ceiling effect was 2.2% for the pain VAS, 1.9% for the disease activity VAS and 1.5% for the well-being VAS.
Equal item-scale correlations (second Likert assumption)
Pearson item-scale correlations corrected for overlap were roughly equivalent for items within a scale for 93% of the PF items, with the exception of item 15 and for 100% of the HRQoL items.
Item internal consistency (third Likert assumption)
Pearson item-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, 0.90 for PF-HW, and 0.84 for PF-US. Cronbach’s alpha was 0.87 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 18 JIA patients, by re-administering both versions (parent and child) of the JAMAR after a median of 7 days (range 7–8 days). The intra-class correlation coefficients (ICC) for the PF total score showed an almost perfect reproducibility (ICC = 0.96). The ICC for the HRQoL PhH showed a substantial reproducibility (ICC = 0.78) and the ICC for the HRQoL-PsH showed an almost perfect reproducibility (ICC = 0.86).
Convergent validity
The Spearman correlation of the PF total score with the JIA core set of outcome variables ranged from 0.4 to 0.5 (median = 0.5). The PF total score best correlation was observed with the parent assessment of pain (r = 0.53, 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 0.6 (median = 0.5), whereas for the PsH ranged from 0.2 to 0.4 (median = 0.3). The HRQoL PhH showed the best correlation with the parent’s assessment of pain (r = 0.64, p < 0.001), while the HRQoL-PsH showed the best correlation with the parent global assessment of well-being (r = 0.43, 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 (0.4–0.5), 0.4 (0.4–0.5), 0.4 (0.4–0.5), respectively.
Discussion
In this study, the Turkish version of the JAMAR was cross-culturally adapted from the original standard English version with three forward and two backward translations. According to the results of the validation analysis, the Turkish 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 HRQoL PhH revealed to be able to discriminate between the different JIA subtypes with the children diagnosed with RF negative poly-arthritis, RF positive poly-arthritis and undifferentiated arthritis having a higher degree of disability.
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 were moderate.
The results obtained for the parent version of the JAMAR are very similar to those obtained for the child version, which suggests that children are equally reliable proxy reporters of their disease and health status as their parents. The JAMAR is aimed to evaluate the side effects of medications and school attendance, which are other dimensions of daily life that were not previously considered by other HRQoL tools. This may provide useful information for intervention and follow-up in health care. In conclusion, the Turkish version of the JAMAR was found to have satisfactory 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 Turkey. 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 thank also Prof. Alberto Martini, PRINTO Chairman. Funding was provided by the Istituto G. Gaslini, Genoa (Italy). Permission for use of JAMAR and its translations must be obtained in writing from PRINTO, Genoa, Italy. All JAMAR-related inquiries should be directed to printo@gaslini.org. Permission for 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. 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. Lahdenne, Dr. Vahasalo, and Dr. Kroger report funding support from Istituto Giannina Gaslini, Genoa, Italy, for the translation and data collection performed at their sites within the EPOCA project., Dr. Consolaro, Dr. Bovis, Dr. Demirkaya, Prof. Ozen, Dr. Sozeri, Dr. Aktay Ayaz, Dr. Kasapcopur, Dr. Unsal, Dr. Makay, Dr. Barut, Dr. Fidanci, Dr. Simsek, and Dr. Cakan 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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