Prognostic factors, disease course and treatment efficacy in Duchenne muscular dystrophy: A systematic review and meta-analysis.

INTRODUCTION/AIMS Prognostic factors in Duchenne muscular dystrophy (DMD) predict the disease course and may help individualize patient care. The aim was to summarize the evidence on prognostic factors that may support treatment decisions. METHODS We searched six databases for prospective studies that each included ≥50 DMD patients with a minimum follow-up of one year. Primary outcomes were age at loss of ambulation (LoA), pulmonary function (forced vital capacity percent of predicted, FVC%p), and heart failure. RESULTS Out of 5074 references, 59 studies were analyzed. Corticosteroid use was associated with a delayed LoA (pooled effect HR 0.42, 95% CI 0.23 to 0.75, I2 94%), better pulmonary function tests (higher peak FVC%, prolonged time with FVC%p >50%, and reduced need for assisted ventilation) and delayed cardiomyopathy. Longer corticosteroid treatment was associated with later LoA (>1 year compared to <1 year; pooled HR: 0.50, 95% CI 0.27 to 0.90) and early treatment start (aged <5 years) may be associated with early cardiomyopathy and higher fracture risk. Genotype appeared to be an independent driver of LoA in some studies. Higher baseline physical function tests (e.g., 6-minute walk test) were associated with delayed LoA. Left ventricular dysfunction and FVC