P3B209: Assessing Delays in Duchenne Muscular Dystrophy Time to Diagnosis: How Early Are You Screening?

Background: The average age of diagnosis for Duchene Muscular Dystrophy (DMD) is 5 years, with a delay of 2.5 years from the first signs of DMD to diagnosis.1 The Centers for Disease Control and Prevention’s (CDC) Learn the Signs. Act Early. program, funded by the American Academy of Pediatrics (AAP), identified age-based developmental screening and ongoing developmental surveillance including milestones for developmental screening practice to discourage a “wait and see” practice.2 Despite these efforts, little is known regarding current DMD screening and diagnosis practices.

Methods: A needs assessment survey was disseminated to a nationally representative audience (primary care providers) to understand DMD screening, referral, and management practices. Data from the 113 respondents was analyzed using mixed methods. Open and closed-ended questions focused on use of screening tools, referral practices, and the clinician’s role in ongoing management.

Results: The survey response rate was 35% (113/325), 44% of respondents were family and internal medicine providers and 35% were pediatricians. About half of the clinicians worked in community practices (49%). Survey results indicated knowledge of appropriate DMD screening tools and tests, but a lack of utilizing these assessments in practice. Majority of respondents (90%) were aware of checking serum creatinine kinase (CK) levels as an initial test to diagnose DMD, but only 17% used it as a primary course of action when suspecting motor delays at 18-months. Testing percentages remained consistent across patient ages with only 18% of providers testing CK levels at 24-months and 15% testing at 30-months. Additionally, about one-third of respondents reported not using a primary screening tool to detect developmental delays at well-child visits. At these visits, providers often selected a “wait and see” approach as their primary course of action when suspecting motor delays (18-months (40%), 24-months (51%), and 30-months (60%)). “Wait and see” respondents (50%) selected to wait 6 -12 months at any age before testing for DMD or referring to a specialist. A thematic analysis of responses to providers’ role in the management of DMD was also conducted. Emergent themes were early detection, referrals, and care coordination, and supporting patients and caregivers.

Conclusion: Providers were knowledgeable about DMD signs, symptoms, and testing. However, self-reported practice data showed a delay in using assessments to improve timely DMD diagnosis and referrals. Delays in diagnosis result in unmet patient needs with further delays in implementation of standards of care, initiation of glucocorticoids, other treatments, genetic counseling, and participation in clinical trials. These preliminary findings emphasize the importance of using screening tools at well-child visits as recommended, followed by a CK test when evaluating a child with motor delays. Earlier screenings and CK tests would help to ensure timely diagnosis and ongoing management of DMD in pediatric patients.