Supplementary Material for: Respiratory and Cardiovascular Readmissions and Prescription Patterns After Spinal Cord Injury: A National Registry-Based Study from Sweden

Introduction:
Spinal cord injury (SCI) is associated with increased risk of cardiovascular and respiratory morbidity, which are major contributors to rehospitalization and mortality. While overall rehospitalization after SCI is well documented, few studies have focused specifically on early cardiopulmonary readmissions or linked these outcomes with prescription patterns using nationwide registry data.
Methods:
We linked the Swedish SCI register (SveReh) to the National Patient Register and Prescribed Drug Register. Adults with new-onset SCI admitted for first-time inpatient rehabilitation between 2016 and 2020 were included (n = 1,196). The cohort was followed for 12 months after discharge. Outcomes were cardiovascular (ICD I) and respiratory (ICD J) readmissions. Kaplan–Meier and Cox regression analyses examined predictors (age, neurological level, pre-SCI drug use). Prescription changes for cardiovascular drugs (ATC C), respiratory drugs (ATC R), and antibiotics (ATC J01) were analyzed 365 days before and after SCI using McNemar’s test.
Results:
Within 12 months, 42 persons (3.5%) were readmitted for cardiovascular and 43 (3.6%) for respiratory causes; >96% remained event-free. Older age predicted both cardiovascular (HR 1.02 per year, 95% CI 1.00–1.05, p = 0.050) and respiratory readmissions (HR 1.02, 95% CI 1.00–1.04, p = 0.024). Neurological level was also associated with respiratory readmission, with highest risk in C1–C4 tetraplegia. Prescription analyses (n = 1173) showed significant increases in antibiotics (+27.7%), cardiovascular drugs (+7.2%), and respiratory drugs (+3.4%).
Conclusion:
Cardiovascular and respiratory readmissions within one year after SCI were uncommon but strongly influenced by age, and for respiratory causes, by neurological level. Marked increases in antibiotic prescriptions highlight infection burden, while cardiovascular prescribing reflected age-related comorbidity. These findings identify subgroups who may benefit from targeted preventive follow-up.