Risk and Protective Factors for Cause-Specific Mortality after Spinal Cord Injury

Abstract Objective To investigate the association of multiple sets of risk and protective factors (biographic and injury, socioeconomic, and health) with cause-specific mortality after spinal cord injury (SCI). Design Retrospective analysis of a prospectively created cohort Setting SCI Model Systems facilities (n=20). Participants 8,157 adults with traumatic SCI who were enrolled in a model systems facility after 1973 and received follow-up evaluation that included all study covariates (between November 1995 and October 2006). Interventions n/a Main Outcome Measure(s) All-cause mortality was determined using the Social Security Death Index as of January 1, 2014. Causes of death were obtained from the National Death Index and classified as infective and parasitic diseases, neoplasms, respiratory system diseases, heart and blood vessel diseases, external causes, and other causes. Competing risks analysis, with time-dependent covariates, was performed with hazard ratios (HR) for each cause of death. Results The HRs for injury severity indicators were highest for deaths due to respiratory system diseases (highest HR for injury level C1-C4: 4.84) and infective and parasitic diseases (highest HR for AIS A: 5.70). In contrast, injury level and AIS were relatively unrelated to death due to neoplasms and external causes. Of the socioeconomic indicators, education and income were significantly predictive of a number of causes of death. Pressure ulcers were the only one of four secondary health condition indicators consistently related to cause of death. Conclusions Injury severity was highly related to mortality due to infectious disease and respiratory complications, suggesting those with the most severe SCI should be targeted for prevention of these causes. Socioeconomic and health factors were more broadly related to a number of causes of death. Intervention strategies that enhance socioeconomic status and health may also result in decreased mortality due to multiple causes.