Stability of Predictors of Mortality after Spinal Cord Injury

OBJECTIVE: To identify the stability of socio-environmental, behavioral, and health predictors of mortality over an eight year time frame. STUDY DESIGN: Cohort study. SETTING: Data were analyzed at a large medical university in the Southeast United States of America (USA). METHODS: Adults with residual impairment from a spinal cord injury (SCI) who were at least one year post-injury at assessment were recruited through a large specialty hospital in the Southeast USA. 1209 participants were included in the final analysis. A piecewise exponential model with 2 equal time intervals (eight years total) was used to assess the stability of the hazard and the predictors over time. RESULTS: The hazard did significantly change over time, where the hazard in the first time interval was significantly lower than the second. There were no interactions between the socio-environmental, behavior, or health factors and time, although there was a significant interaction between age at injury (a demographic variable) and time. CONCLUSION: These results suggest there is stability in the association between the predictors and mortality, even over an eight year time period. Results reinforce the use of historic variables for prediction of mortality in persons with SCI.