Prevalence of healthcare conditions and services used by patients with myotonic dystrophy pre-and post-diagnosis, a real-world data analysis



Poster Number: 74


John Day, MD, PhD, Stanford University Medical Center, Kathryn Munoz, Avidity Biosciences, Inc., Richard Brook, Better Health Worldwide, Inc, Brad McEvoy, Avidity Biosciences, Li-Jung Tai, Avidity Biosciences, Kelly DiTrapani, Avidity Biosciences, Inc., Nathan Kleinman, Better Health Worldwide, Chao-Yin Chen, Avidity Biosciences, Mark Stahl, Avidity Biosciences, Inc.

Describe the changes in outcomes (healthcare conditions, services, costs, and care days) for patients with myotonic dystrophy compared with matched controls (MCs) two years post-pre diagnosis.

Myotonic dystrophy (DM, Types 1 and 2) are dominantly inherited multisystem disorders that cause progressive weakness and myotonia along with variable cardiopulmonary, gastrointestinal, endocrine, and neurological manifestations that adversely affect quality of life. Literature describing the DM patient journey is limited.

We used PharMetrics deidentified-US-claims (Jan-2010—Mar-2021) to retrospectively evaluate outcomes for DM-patients vs non-DM MCs. DM-patients had ?2 DM claims ?30 days apart (index date=first diagnosis date). Cohorts were matched (5-MC:1-DM) on index date, age, region, gender, plan, and payer types. Outcomes were compared two-years post-diagnosis minus two-years pre-diagnosis (Post-PreDx) using US Agency for Healthcare Research & Quality (AHRQ) categories. Data reported is per-member-per-year. All reported findings significant (p<0.05).

We identified 519 DM-patients and 2595 MCs. Most outcomes demonstrated higher care utilization in DM-patients than MCs. Post-PreDx care days increased at all service settings except lab for both cohorts (?9.9 DM;?1.5 MCs). Post-PreDx DM-patients’ AHRQ-prevalence changed in 58(?57;?1) categories led by “other nervous system disorders” (37.6% DM;3.2% MCs), “cardiac dysrhythmias” (17.3% DM;2.3% MCs) and “other lower respiratory disease” (16.0% DM;2.7% MCs). DM-patients’ mean number of services increased Post-PreDx (21.3;2.9 MCs). Post-PreDx DM-patients' utilization increased in 21 AHRQ-service and 7 AHRQ-cost categories. Total medical and drug costs increased for DM-patients’ ($18,705 to $25,594) vs MCs ($5640 to $6884).

Health care utilization increased significantly in DM patients following diagnosis and was overall both higher and in different categories than MCs. This likely reflects the need to investigate and manage previously unsuspected manifestations of DM following formal diagnosis.