The cooperative international neuromuscular research group Duchenne natural history study--a longitudinal investigation in the era of glucocorticoid therapy: design of protocol and the methods used.

UNLABELLED Contemporary natural history data in Duchenne muscular dystrophy (DMD) is needed to assess care recommendations and aid in planning future trials. METHODS The Cooperative International Neuromuscular Research Group (CINRG) DMD Natural History Study (DMD-NHS) enrolled 340 individuals, aged 2-28 years, with DMD in a longitudinal, observational study at 20 centers. Assessments obtained every 3 months for 1 year, at 18 months, and annually thereafter included: clinical history; anthropometrics; goniometry; manual muscle testing; quantitative muscle strength; timed function tests; pulmonary function; and patient-reported outcomes/health-related quality-of-life instruments. RESULTS Glucocorticoid (GC) use at baseline was 62% present, 14% past, and 24% GC-naive. In those ≥6 years of age, 16% lost ambulation over the first 12 months (mean age 10.8 years). CONCLUSIONS Detailed information on the study methodology of the CINRG DMD-NHS lays the groundwork for future analyses of prospective longitudinal natural history data. These data will assist investigators in designing clinical trials of novel therapeutics.