Gainful employment and risk of mortality after spinal cord injury: effects beyond that of demographic, injury and socioeconomic factors

Objective: To evaluate the association of three levels of gainful employment with the risk of mortality after traumatic spinal cord injury (SCI) while controlling for known predictors of mortality status (including education and income). Study design: Prospective cohort study Setting: A total of 20 federally funded SCI Model Systems of care in the United States. Methods: Participants included 7955 adults with traumatic SCI. Preliminary assessments were conducted between 1995 and 2006. Mortality status was determined by the Social Security Death Index (1308 deaths). A two-stage logistic regression model was used to estimate the chance of dying in any given year. Life expectancy was calculated under different economic assumptions. Results: Compared with those who were working 30 + h per week, the odds of mortality was 1.37 for those who worked 1-29 h and 1.67 for those who were unemployed. The addition of gainful employment only modestly reduced the effects of household income and education, both of which remained significant. For instance, the odds of mortality for household income (referent $75 000 +) decreased from 1.50 to 1.38 for $25 000-$75 000 and from 2.10 to 1.82 for <$25 000. Life expectancy varied widely depending on socioeconomic characteristics more than doubling under certain assumptions. Conclusion: Substantial variation in mortality is attributable to employment, above and beyond the effects of previously established demographic, injury and socioeconomic predictors. Although some excess mortality may be the inevitable consequence of SCI, risk is substantially increased with poor socioeconomic characteristics. Spinal Cord (2012) 50, 784-788; doi:10.1038/sc.2012.49; published online 1 May 2012