Incident Traumatic Spinal Cord Injury and Risk of Alzheimer’s Disease and Related Dementia: Longitudinal Case and Control Cohort Study

Abstract

Abstract Background: Prevalent traumatic spinal cord injury (TSCI) is associated with Alzheimer’s disease and related dementia (ADRD). Study Design: Retrospective case/control longitudinal cohort study Objective: To examine the hazard ratio for ADRD after incident TSCI. We hypothesized that ADRD hazard is greater among adults with incident TSCI compared with their matched control of adults without TSCI. Setting: Using 2010-2020 U.S. national private administrative claims data, we identified adults aged 45 years and older with probable (likely and highly likely) incident TSCI (n=657). Our controls included one-to-ten matched cohort of people without TSCI (n=6,553). Methods: We applied Cox survival models and adjusted them for age, sex, years of living with certain chronic conditions, exposure to six classes of prescribed medications, and neighborhood characteristics of place of residence. Hazard ratios were used to compare the results within a 4-year follow-up. Results: Our fully adjusted model without any interaction showed that incident TSCI increased the risk for ADRD (HR=1.30; 95% CI: 1.01-1.67). People aged 45-64 with incident TSCI were at high risk for ADRD (HR=5.14; 95% CI:2.27-11.67) and no significant risk after age 65 (HR=1.20; 95% CI: .92-1.55). Our sensitivity analyses confirmed a higher hazard ratio for ADRD after incident TSCI at 45-64 years of age compared with the matched controls. Conclusion: Incident TSCI increased the hazard for ADRD for people aged 45-64 at the time of injury. This study informs the need to update clinical guidelines such as cognitive screening and cognitive rehabilitation to preserve cognition or slow the potential progression of ADRD.