Epidemiological characteristics of patients with juvenile dermatomyositis in China: a multicenter study.

OBJECTIVE Juvenile dermatomyositis (JDM) is a rare but chronic autoimmune disease with systemic nonsuppurative inflammation. Many studies have focused on the clinical characteristics and therapy of JDM. A few studies have reported the epidemiological characteristics and social burden of JDM patients abroad, but there has been no study in China. METHODS This study was based on the FUTang Updating medical REcords Database. Data was extracted from the registry information of inpatient medical records. The epidemiological characteristics and economic burden of Chinese JDM patients were analyzed. RESULTS A total of 1164 JDM patients from 24 hospitals were enrolled from Jan 2016 to Dec 2021. The ratio of boys to girls was 1:1.23, and half were between 6 and 12 years old. Over half(n=629) were admitted to the hospital at least twice for intensive treatment. 20% of JDM patients suffered from lung involvement and 2.2% suffered from subcutaneous calcification. The median days of hospitalization were 10 (range 6 to 14), in addition, the median United States dollar (USD) of expense was 2370.5(1373.7,3541.9). Lung involvement was the major factor causing high inpatient burden, length of stay, and expense. Nearly, 17% of JDM patients were admitted to the hospital as emergencies, suggesting sever disease activity stage needing urgent treatment. No deaths occurred in our study. CONCLUSION Our study documents the epidemiological characteristics and social burden of JDM patients in China, contributing to the enhanced comprehension and effective management of JDM in the country.