Race, Income, and Disease Outcomes in Juvenile Dermatomyositis

Objective: To determine the relationships among race, income, and disease outcomes in children with juvenile dermatomyositis (JDM).

Study Design: Data from 438 subjects with JDM enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Legacy Registry were analyzed. Demographic data included age, sex, race, annual family income, and insurance status. Clinical outcomes included muscle strength, presence of rash, calcinosis, weakness, physical function, and quality of life measures. Disease outcomes were compared based on race and income.

Results: Minority subjects were significantly more likely to have low annual family income and significantly worse scores on measures of physical function, disease activity, and quality of life measures. Subjects with lower annual family income had worse scores on measures of physical function, disease activity, and quality of life scores, as well as weakness. Black subjects were more likely to have calcinosis. Despite these differences in outcome measures, there were no significant differences among the racial groups in time to diagnosis or duration of disease. Using calcinosis as a marker of disease morbidity, black race, annual family income <$50 000 per year, negative antinuclear antibody, and delay in diagnosis >12 months were associated with calcinosis.

Conclusion: Minority race and lower family income are associated with worse morbidity and outcomes in subjects with JDM. Calcinosis was more common in black subjects. Further studies are needed to examine these associations in more detail, to support efforts to address health disparities in subjects with JDM and improve disease outcomes.