Health-related quality of life of patients with juvenile dermatomyositis: results from the paediatric rheumatology international trials organisation multinational quality of life cohort study

Objective. To investigate the health-related quality of life (HRQOL) change over time, as measured by the Child Health Questionnaire (CHQ), and its determinants in patients with active juvenile dermatomyositis (DM). Methods. We assessed patients with juvenile DM at both baseline and 6 months of followup, and healthy children age ≤18 years. Potential determinants of poor HRQOL included demographic data, physician's and parent's global assessments, muscle strength, functional ability as measured by the Childhood Health Assessment Questionnaire (C-HAQ), global disease activity assessments, and laboratory markers. Results. A total of 272 children with juvenile DM and 2,288 healthy children were enrolled from 37 countries. The mean ± SD CHQ physical and psychosocial summary scores were significantly lower in children with juvenile DM (33.7 ± 11.7 versus 54.6 ± 4.1) than in healthy children (45.1 ± 9.0 versus 52 ± 7.2), with physical well-being domains being the most impaired. HRQOL improved over time in responders to treatment and remained unchanged or worsened in nonresponders. Both physical and psychosocial summary scores decreased with increasing levels of disease activity, muscle strength, and parent's evaluation of the child's overall well-being. A C-HAQ score >1.6 (odds ratio [OR] 5.06, 95% confidence interval [95% CI] 2.03-12.59), child's overall well-being score >6.2 (OR 5.24, 95% CI 2.27-12.10), and to a lesser extent muscle strength and alanine aminotransferase level were the strongest determinants of poor physical well-being at baseline. Baseline disability and longer disease duration were the major determinants for poor physical well-being at followup. Conclusion. We found that patients with juvenile DM have a significant impairment in their HRQOL compared with healthy peers, particularly in the physical domain. Physical well-being was mostly affected by the level of functional impairment.