OBJECTIVES : Spinal muscular atrophy (SMA) is a rare genetic and life-threatening neuromuscular disease. Data on the cost burden of SMA type 1 for US health plans is limited.

METHODS : A retrospective analysis was conducted to estimate the economic burden of SMA type 1 using QuintilesIMS’s PharMetrics Plus Health Plan Claims Database. Infants with ICD-9 codes for SMA ≤1 year old were classified as SMA type 1 (N=119) and matched (1:1) according to age, gender, index year, and Charlson Comorbidity Index with a random sample of infants without SMA type 1. All-cause healthcare resource utilization (HCRU) and costs (pharmacy, outpatient, and/or inpatient/hospitalization) incurred between February 2011 and November 2016 during the post-index/follow-up period (≥30 days up to 360 days) were compared. Death was assumed if select events (eg, cardiac arrest/failure) occurred during the last month in which claims were available.

RESULTS : Significantly more SMA infants (98.32%) received ≥1 all-cause pharmacy, outpatient, or in-patient services during the post-index period compared to matched infants (54.62%; P<0.0001). Mean per-patient-per-month (PPPM) all-cause HCRU was significantly higher for SMA infants: pharmacy (1.43 vs 0.37 prescriptions), outpatient (14.10 vs 2.17 services), in-patient (0.23 vs 0.003 admissions) (all, P<0.0001). Mean PPPM hospitalizations (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 SMA infants (all, P<0.0001). Subsequently, all-cause pharmacy, outpatient, and inpatient costs PPPM were significantly greater in SMA infants ($371 vs $20; $4,192 vs $232; and $22,500 vs $22, respectively [all, P<0.0001]) resulting in extrapolated all-cause annual cost per patient of $324,751 (SMA) vs $3,294 (matched).

CONCLUSIONS : The economic burden of SMA type 1 to US health plans is substantial; a treatment that alters the early natural course of disease is needed and might result in long-term cost savings.