Epidemiology of spinal cord injury and spinal cord injury-induced urinary tract stones in Taiwan: A 2005-2015 population-based cohort study

Context: Patients with spinal cord injury (SCI) can develop urinary tract stones (UTSs) up to years after the injury, which is especially common in the first few months. However, relevant epidemiological studies and up-to-date epidemiological data for SCI in Taiwan are lacking.Purpose: To estimate SCI and SCI-induced UTS incidence and trauma severity, neurological deficits, and injury site in patients with SCI-induced UTSs in Taiwan.Design: Retrospective cohort study.Patient sample: Taiwan National Health Insurance Research Database (NHIRD) data and death data from the Department of Health and Welfare Data Science Center (HWDC) collected over 2005-2015 from 13,977 patients with SCI aged >18 years.Outcome measures: Cumulative incidence (CI), incidence density (ID), relative ratios (RRs), odds ratios (ORs), and hazard ratios (HRs) were measured.Methods: By using Cox regression, we assessed UTS risk in patients with SCI.Results: Although standardized SCI incidence demonstrated a decreasing trend annually, the average annual incidence remained at 60.4 per million. Most (65.7%) of the included patients were men. SCI incidence was 1.98 times higher in men than in women. The most common injury site was the cervical spine (63.8%); the incidence at this site was 2.83 times higher in men than in women. Most (76.1%) of the patients had traumatic SCI (TSCI), and the standardized incidence of TSCI and non-TSCI was 45.9 and 14.4 per million, respectively. 46.1% of the patients had severe SCI (RISS >= 16). Over the 11-year follow-up period, UTSs occurred in 10.4% of the patients, with a standardized incidence of 2.39 per 100 person-years, and UTS risk was 1.56 times higher in men than in women. Age of 45-65 years, SCIs at multiple sites, and neurological deficits (e.g. paraplegia) were noted to be UTS risk factors. Finally, UTS onset mainly occurred in the first year after SCI.Conclusion: The risk of UTS among patients with SCI is influenced by age, sex, injury site, and paraplegia but not by paralysis resulting from other neurological deficits. Even though SCI incidence is declining annually, severe SCI remains a significant issue. Therefore, continuing to reduce SCI incidence and strengthening urinary tract management in patients with SCI are essential for reducing UTS occurrence and their impact on health.