Comparative All-Cause Mortality Among a Large Population of Patients with Spinal Muscular Atrophy Versus Matched...

Area of Science:

• Neurology
• Genetics
• Public Health

Background:

• Limited data exists on adult survival rates for spinal muscular atrophy (SMA).
• Population-based survival data for SMA patients, especially into adulthood, is scarce.
• This study investigates mortality rates in SMA patients using electronic health records from the pre-treatment era.

Purpose of the Study:

• To estimate and compare age-specific, all-cause mortality rates in spinal muscular atrophy (SMA) patients versus matched controls.
• To analyze survival data from a large, retrospective cohort in the pre-treatment era.
• To provide insights into the long-term prognosis of SMA.

Main Methods:

• Utilized the US Optum® de-identified electronic health records (EHR) database (approx. 104 million individuals).
• Identified SMA cases using ICD-9/10 codes and matched them 10:1 to controls without SMA diagnosis.
• Calculated age-specific mortality rates per person-year (PY) and hazard ratios.

Main Results:

• Analyzed 5,179 SMA cases and 51,152 controls; overall hazard ratio for SMA cases was 1.76.
• SMA patients, including those with Type III codes, showed higher mortality rates (1059/100,000 PYs) than controls (603/100,000 PYs).
• Mortality rates for SMA cases consistently exceeded controls across all adult age groups (13-60+ years).

Conclusions:

• Spinal muscular atrophy (SMA) patients of all ages, including adults and Type III, exhibited increased all-cause mortality.
• Findings are based on the pre-treatment era, indicating higher mortality risks before therapeutic interventions.
• The study underscores the significant survival impact of SMA.