Inpatient, Outpatient Costs of SMA Are “Tremendous,” Study Highlights

Direct inpatient and outpatient costs are significantly higher for patients with untreated spinal muscular atrophy (SMA) compared with matched controls, according to a paper published in Journal of Market Access and Health Policy. Infantile SMA, which is the most severe form of the disease, has the highest costs, exceeding $100,000 inpatient costs per patient annually.

SMA is a rare disease that occurs in about 1 in 11,000 live births, and severe cases cause trouble with breathing and swallowing, paralysis, and death. In severe cases, the life expectancy is less than 2 years; in cases of intermediate severity, the life expectancy extends into adulthood; and in cases of mild severity, patients have a normal life expectancy.

There are now 3 FDA-approved therapies: nusinersen approved December 2016, onasemnogene abeparvovex-xioi approved May 2019, and risdiplam approved August 2020. Before the approval of these therapies, standard-of-care treatment included neurologic, respiratory, orthopedic, gastrointestinal, and nutritional support, as well as physical and occupational therapy.

“As new treatments continue to become available, the economic impact of SMA on patients and health care systems has been debated,” the authors wrote, noting that there has been a limited amount of economic data.

The authors analyzed a claims database to evaluate the direct costs of managing SMA in the 4 years prior to the approval of the first therapy. “These results will provide insights into the economic burden of SMA and can provide baseline data to allow researchers to track cost-related changes over time as the use of new treatments increases,” they wrote.

The study included 7961 patients with at least 1 SMA claim. They were categorized as either having infantile, child, or juvenile SMA, instead of using the traditional type I/II/III categorization because of the limitations of insurance claims data. The patients with SMA were matched 1:1 based on birth year, gender, and geographic region with controls who did not have SMA.

Analysis of the patients with infantile SMA found that 60.3% had an inpatient claim during the study period compared with just 1.7% of controls. The mean length of stay for patients with infantile SMA was 10 days, and respiratory illness was the most common reason for the inpatient admission. The mean annualized total net payments for inpatient admissions for the infantile SMA cohort was $118,609 compared with just $59 for the control group.

Inpatient claims were also significantly more common among the child SMA group: 35.7% compared with 3.6% of controls. The mean length of stay was 6.7 days for the child SMA cases compared with 1 day for the controls, and the most common reason for the inpatient admission among child SMA cases was respiratory illness. The mean annualized total net payments for inpatient admissions was $26,940 for the SMA cases compared with just $144 for the controls.

The findings were similar for the juvenile SMA cohort, which had inpatient claims for 47.0% of cases compared with 4.3% of controls. The mean length of stay for the juvenile SMA cases was the shortest among the SMA cohorts: 5.8 days compared with 4.4 days for controls. The mean annualized total net payments for inpatient admissions was $39,390 for juvenile SMA cases compared with $701 for controls. Again, respiratory illness was the most common reasons for an inpatient admission among the juvenile SMA cohort.

However, for both child and juvenile SMA, outpatient admissions were bigger drivers of cost. The mean number of outpatient claims per person per year was 248.7 for the child SMA cohort and 170.3 for the juvenile SMA cohort. Mean net payments were $73,094 in the child SMA cohort, or 73% of the total inpatient and outpatient costs, and $49,068 in the juvenile SMA cohort, or 55% of the total costs. For the infantile SMA cohort, outpatient payments accounted for 32% of the costs.

The authors noted that mortality data were not captured, but as treatments improve outcomes and survival, the overall and long-term costs of SMA may be underestimated. The costs in this study also did not take into account the burden incurred by patients and their families; for instance, they may spend money on equipment to improve mobility and accessibility, which may require home renovations.

“Uniform adoption and implementation of the current standards of care guidelines could result in fewer complications of SMA,” the authors concluded. “In addition, the availability of new treatments and spread SMA newborn screening has the potential to not only reduce the economic burden of SMA but also to significantly improve long-term clinical outcomes and patient and caregiver quality of life.”

Reference

Belter L, Cruz R, Kulas S, McGinnis E, Dabbous O, Jarecki J. Economic burden of spinal muscular atrophy: an analysis of claims data. J Mark Access Health Policy. Published online November 8, 2020. doi:10.1080/20016689.2020.1843277