SMA CLINICAL DATA, OUTCOME MEASURES AND REGISTRIES: P.95Economic burden of infant-onset (type 1) spinal muscular atrophy: a retrospective claims database analysis

Abstract

Spinal muscular atrophy (SMA) is a rare genetic, life-threatening neuromuscular disease. Data on the cost burden of SMA type 1 (SMA1) for U.S. health plans are limited as most studies do not differentiate between SMA types or have consisted of a post-hoc subset based on age at diagnosis. This retrospective analysis estimated the economic burden of SMA1 using QuintilesIMS's PharMetrics Plus Health Plan Claims Database. Infants with ICD-9 codes for SMA ≤1 year old were classified as SMA1 (N=119) and matched (1:1) with a random sample of infants by age, gender, index year, and Charlson Comorbidity Index (CCI). Healthcare resource utilization (HCRU) and costs (pharmacy, outpatient, and inpatient/hospitalization) incurred between February 2011 and November 2016 during the post-index/follow-up period (≥30 days up to 360 days) were compared. Significantly more SMA1 patients (98.32%) received ≥1 pharmacy, outpatient, or in-patient services (54.62%; P<0.0001). Mean per-patient-per-month (PPPM) all-cause HCRU was significantly higher for SMA1 infants: pharmacy (1.43 vs. 0.37 prescriptions); outpatient (14.10 vs. 2.17 services); and in-patient (0.23 vs. 0.003 admissions) (all, P<0.0001). Mean PPPM hospital admissions (0.23 vs. 0.003), length of hospital stay (6.93 vs. 0.09 days), procedures per admission (1.49 vs. 0.03), and readmissions (0.04 vs. 0.00) were also significantly greater for SMA1 infants (all, P<0.0001). Pharmacy, outpatient, and inpatient costs PPPM were significantly greater in SMA1 infants ($371 vs. $20; $4,192 vs. $232; and $22,500 vs. $22, respectively [all, P<0.0001]), resulting in extrapolated all-cause total annual costs of $324,751 (SMA1 cohort) vs. $3,294 (matched cohort). The economic burden of SMA1 is substantial; a treatment that alters the early natural course of the disease might result in long-term cost savings.