OBJECTIVES: In recent decades, advancements to standards of care of Duchenne muscular dystrophy (DMD), a rare, genetic disease characterized by progressive muscle degeneration, have resulted in significant improvements to life expectancy. As a consequence, it has become more pressing to study and treat manifestation and complications emerging in advanced stages of DMD. The objectives of our study were to review, synthesize, and grade published evidence of predictors of outcomes measured after loss of ambulation in DMD.

METHODS: We searched MEDLINE, Embase, and the Cochrane Library for records of studies published from inception up until May 31, 2021, reporting evidence of predictors of outcomes measured after loss of ambulation in DMD. Identified predictors were synthesized into six outcome categories: cardiac health and function, gastrointestinal health, mental health, respiratory health and function, survival, and upper extremity function. Levels of evidence were established with the grading system of the Centre for Evidence-Based Medicine.

RESULTS: A total of 83 publications were included for data extraction, synthesis, and grading. Predictors of cardiac health and function included body mass index, cardiac medication (i.e., angiotensin-converting enzyme inhibitors and β-blockers), carvedilol, DMD genetic modifiers, DMD mutation type, glucocorticoid exposure, idebenone, and ventilation support. Predictors of respiratory health and function included ataluren, DMD genetic modifiers, DMD mutation type, eteplirsen, glucocorticoid exposure, idebenone, ventilation support, and weight. Predictors of survival included cardiac medication, glucocorticoid exposure, ventilation support, and spinal surgery. Predictors of upper extremity function included glucocorticoid exposure and ATL1102 (an antisense oligonucleotide). We found no predictors of gastrointestinal or mental health. Of all publications, 60% were of low quality, 10% of moderate quality, and 30% of high quality.

CONCLUSIONS: Our review delineates predictors of outcomes measured after loss of ambulation in DMD and helps raise awareness of relationships between complications, milestones, and clinical interventions across stages of the disease.