Shifting Hospitalization Patterns in Pediatric Spinal Muscular Atrophy in the Post-Spinraza Era

Introduction: Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder historically managed with supportive care. Nusinersen (Spinraza), approved in 2016, was the first disease‑modifying therapy that improved infant motor outcomes; yet, access disparities persist, especially for lower‑income or publicly insured children. We examined if Spinraza availability altered medical technology use and palliative care referral rates, and if socioeconomic factors (SES) influenced access and outcomes.


Methods: We conducted a retrospective cohort study using the Pediatric Health Information System (PHIS) to identify patients aged ≤21 with SMA by ICD‑9/10 codes from 2003–2023. Patients admitted before or after 12/26/2016 were classified as pre‑ and post‑Spinraza, respectively; Spinraza use was determined by inpatient pharmacy billing. Outcomes included palliative care consultation, tracheostomy, mechanical ventilation, feeding tube placement, and hospital length of stay. Comparisons used chi‑square tests (p < 0.05), and multivariable logistic regression assessed associations between Spinraza and outcomes, adjusting for SES (ZIP‑code–linked income quintiles from the American Community Survey), age, sex, race, ethnicity, and insurance type.


Results: Of 4,197 SMA patients (2,770 pre‑ and 1,427 post‑Spinraza), 11.6% received Spinraza. While 0–3 day admissions rose, 8-14 day stays decreased (44.0% to 51.1%, 14.6% to 10.2%, p< 0.001). Post-Spinraza increased palliative care and feeding tube use (3.9% to 6.4%, 25.7% to 31.9%, p< 0.001), while tracheostomy had no change (12.4% to 11.6%, p=0.338). Mechanical ventilation rates declined (36.0% to 30.2%, p< 0.001), and Spinraza use lowered odds of mechanical ventilation (OR 0.53, 95% CI 0.36–0.78, p< 0.001). Public insurance was associated with higher odds of tracheostomy, feeding tube placement, mechanical ventilation, and palliative care (ORs 1.39–1.83, p≤0.041); no other associations were found.


Conclusions: Hospitalizations post-Spinraza had higher feeding tube and palliative care rates but shorter stays and lower mechanical ventilation rates. Spinraza independently reduced mechanical ventilation rates, and while SES quintiles showed no association, public insurance predicted higher technology use and palliative care, highlighting the need for broader Spinraza access.