OBJECTIVES: Duchenne muscular dystrophy (DMD) is a rare, severely debilitating and ultimately fatal genetic disease characterized by progressive muscle degeneration. Following improvements to life expectancy in DMD, the medical management of the disease has shifted to more anticipatory therapeutic strategies to achieve prevention, early identification, and treatment of complications. The objectives of our study were to review, synthesize, and grade published evidence of the impact of the timing of initiation of clinical interventions in DMD.

METHODS: We searched PubMed, Embase, and the Cochrane Library for records of studies published from inception up until November 19, 2021, reporting evidence of the impact of the timing of initiation of clinical interventions in DMD. We synthesised extracted evidence into nine outcome categories: cardiac health and function; gastrointestinal health; lower extremity and motor function; mental health; respiratory health and function; scoliosis; survival; upper extremity function; and weight, height, and BMI. We assessed the quality of evidence using the GRADE framework.

RESULTS: We included 11 publications encompassing 1,692 patients with DMD from seven countries (Australia, France, Germany, Italy, Japan, the United Kingdom, and the United States of America). Six (55%) studies reported evidence of an impact of the timing of initiation of glucocorticoids on loss of ambulation, cardiomyopathy, fractures, forced vital capacity, and height and BMI; four (36%) of cardiac medication (i.e., angiotensin-converting enzyme inhibitors, β-blockers, and eplerenone) on left ventricular size and function and survival; and one (9%) of lower limb surgery on motor quotients. The overall quality of the body of evidence was low.

CONCLUSIONS: We show that the evidence of the impact of the timing of initiation of clinical interventions in patients with DMD is scarce and of generally low quality. Further research of this topic is warranted to help inform treatment guidelines in this indication.