Background: Diagnostic delay in Duchenne Muscular Dystrophy (DMD) results in lost opportunities for early intervention, and initiation of multidisciplinary care and corticosteroid treatment. Newborn screening allows for early detection enabling timely intervention that can potentially slow the progression. We aimed to study if later diagnoses lead to earlier loss of ambulation in boys with DMD.
Methods: Retrospective chart review of patients with DMD followed at Arkansas Children’s Hospital was conducted. Logistic regression was used to determine if time between age at onset of symptoms and age at diagnosis was associated with loss of ambulation. Additionally, demographic variables were examined for association with loss of ambulation.
Results: Data were obtained on 78 (40 ambulatory and 38 non ambulatory) patients. 52 patients were identified as White, non-Hispanic (66.7%), 15 identified as Hispanic (19.2%), 4 identified as Black, non-Hispanic (5.1%), 2 identified as Asian or Pacific Islander (2.6%), and 5 identified as other or unknown (6.4%). The average age at onset of symptoms was 3.2 years and at diagnosis was 4.6 years respectively. The average age at diagnosis was 3.6 and 5.6 years for ambulatory and non-ambulatory patients, respectively. The average age at start of multidisciplinary care was 4.8 years. Age at diagnosis and white race were significantly associated with loss of ambulation. For every 2-year increase in the age at diagnosis, the odds of loss of ambulation increased by 2.6 (CI: 1.5 – 4.3; p < .001). The odds of white, non-Hispanic patients reaching loss of ambulation was 3.8 times greater (95% CI: 1.2 to 12.5; p=.028) than those of non-white race or Hispanic ethnicity. Conclusion: Older age at diagnosis and white race moderately predicated loss of ambulation. Further studies with larger sample sizes are needed.