The economic burden of spinal muscular atrophy

Aim: To evaluate the economic burden of spinal muscular atrophy (SMA).

Materials and methods: This study used Department of Defense Military Healthcare System (MHS) data from 2003-2012. Healthcare costs were determined for patients with at least one inpatient or three outpatient claims with a diagnosis of SMA before 18 years of age and who had ≥ 6 months of data after first SMA diagnosis or expired within 6 months of initial diagnosis. A comparator cohort was selected using a 3:1 match based on age and gender.

Results: A total of 239 individuals with SMA diagnosis met the inclusion criteria along with 717 matched comparator patients. More patients with SMA had hospitalizations (69.5%) compared to the comparator cohort (17.2%, p < 0.001). Median total expenditures across all years of data for patients with SMA were $83 652 (25-75th percentile = $29 620-228 754) vs the comparator group of $4329 (25-75(th) percentile = $1229-10 062 (p < 0.001)) over an average (SD) of 6.9 ± 3.6 years. The annualized mean costs of total healthcare expenditures were significantly higher for the SMA cases than the comparison cohort, $47 862 ± 88 607 compared to $1861 ± 6374, respectively (p < 0.001). The sub-group of patients with early diagnosis (n = 45) had 4.3 ± 2.9 years of observation with a median cost of $167 921 ($53 349-678 412). Mean age (SD) at first observed SMA diagnosis was 7.5 ± 6.4 years. Mean (SD) duration of follow-up after initial SMA diagnosis was 4.8 ± 3.3 years, with a median post-diagnosis cost of $60 213 ($18 229-192 559). The major costs for all patients were outpatient visits [median = $53 152 ($23 902-136 150)], followed by inpatient costs [median = $11 258 ($0-51 987)] and total prescription costs [median = $3167 ($943-13 283)].

Limitations: The analysis is limited to the data available and may under-estimate the total cost of SMA.

Conclusions: Individuals with SMA have a high degree of morbidity, particularly those diagnosed during infancy. SMA patients have significant medical expenditures and high utilization of healthcare services.