Income and risk of mortality after spinal cord injury.

OBJECTIVE

To evaluate the association of household income and formal education with risk of mortality after spinal cord injury (SCI).

DESIGN

Cohort study.

SETTING

Twenty hospitals designated as Model SCI Systems of care in the United States.

PARTICIPANTS

Adults (N=8027) with traumatic SCI, seen in one of the Model SCI Systems, who had at least 1 follow-up assessment between 1995 and 2006. All participants were at least 1 year postinjury at the time of assessment. There were 57,957 person-years and 1036 deaths. The follow-up period started with the first assessment between 1995 and 2006 and went until either the date of death or March 2009.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Mortality status was determined by routine follow-up supplemented by using the Social Security Death Index. A logistic regression model was developed to estimate the chance of dying in any given year.

RESULTS

Educational status and income were significantly predictive of mortality after adjusting for age, sex, race, and severity of injury. Compared with those with household income of $75,000 or greater, the odds of mortality was greater for those who had income between $25,000 and $75,000 (1.61) and still higher for those with less than $25,000 a year (2.41). Life expectancy differed more as a function of household income than the economic subscale of the Craig Handicap Assessment and Reporting Technique.

CONCLUSION

There was a clear gradation in survival based on familial income (high, middle, low), not just an effect of the lowest income.