CHARACTERIZATION OF SPINAL MUSCULAR ATROPHY POPULATION IN A LARGE US FULLY-INSURED HEALTH PLAN POPULATION

OBJECTIVES: Characterize a spinal muscular atrophy (SMA) population to identify SMA utilization patterns based on demographics within a large US health plan. METHODS: Descriptive statistics were generated from retrospective analysis on medical and pharmacy claims from Aetna fully-insured commercial and Medicare members between January, 2013 and August, 2016 with an ICD-9/ 10 code for SMA without age restrictions. Additional analyses were performed to improve specificity due to potential provider miscoding and rule-out claims by comparing members identified with 1 vs. 2 claims of SMA to increase the likelihood of accurate SMA coding. Further specificity analyses were performed to determine the percentage of members with > 1 SMA claim having another SMA claim or followed by a claim for amyotrophic lateral sclerosis, muscular dystrophy, or non-SMA anterior horn disease ('SMA-like conditions'). RESULTS: A total of 3,145 unique members with at least one month's eligibility following their Index Date were identified based on >1 ICD-9/10 and 438 unique members based on > 2 ICD-9/10 claims for SMA, respectively. Of the total group, 96% (>1 claims) and 80% (>2 claims) were age 18 and older. Age at first SMA claim ('Index Date') may not reflect initial diagnosis. Only 2.5% of the > 1 claims population later showed claims for an SMA-like condition. CONCLUSIONS: The >2 claims population had more per-patient inpatient and ER visits, and less outpatient claims, health resource utilization (HRU) and generally higher costs, compared with the >1 claims population. These health services differences may be due to increased likelihood of having SMA, greater concentration of younger members, and/or increased SMA HRU. This analysis provides insight into real-world SMA patient journey through costs and health services utilization considerations for managing SMA and the usefulness of claims data for identifying and characterizing patients with this rare and often devastating condition.