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.

<bold>Unlabelled: </bold>Contemporary natural history data in Duchenne muscular dystrophy (DMD) is needed to assess care recommendations and aid in planning future trials.<bold>Methods: </bold>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.<bold>Results: </bold>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).<bold>Conclusions: </bold>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. [ABSTRACT FROM AUTHOR]