Lower education and income predict worse long-term outcomes after injury.

BACKGROUND: Lower socioeconomic status (SES) is known to be associated with higher morbidity and mortality following injury. However, the impact of individual SES on long-term outcomes after trauma is unknown. The objective of this study was to determine the impact of educational level and income on long-term outcomes after injury. METHODS: Trauma patients with moderate to severe injuries admitted to three Level-I trauma centers were contacted 6 months to 12 months after injury to evaluate functional status, return to work/school, chronic pain, and posttraumatic stress disorder (PTSD). Lower SES status was determined by educational level and income. Adjusted logistic regression models were built to determine the association between educational level and income (lowest vs. highest quartile determined by census-tract area) on each of the long-term outcomes. A sensitivity analysis was performed using the national median household income ($57,617) as threshold for defining low versus high income. RESULTS: A total of 1,516 patients were followed during a 36-month period. Forty-nine percent had a low educational level, and 26% were categorized in the low-income group. Mean (SD) age and injury severity score were 60 (21.5) and 14.3 (7.3), respectively, with most patients (94%) having blunt injuries. After adjusting for confounders, low educational level was associated with poor long-term outcomes: functional limitation [odds ratio (OR), 1.78 (95% confidence interval (CI), 1.41-2.26)], has not yet returned to work/school [OR, 2.48 (95% CI, 1.70-3.62)], chronic pain [OR, 1.63 (95% CI, 1.27-2.10)], and PTSD [OR, 2.23 (95% CI, 1.60-3.11)]. Similarly, low-income level was associated with not yet return to work/school [OR, 1.97 (95% CI, 1.09-3.56)], chronic pain [OR,1.70 (95% CI, 1.14-2.53)], and PTSD [OR, 2.20 (95% CI, 1.21-3.98)]. In sensitivity analyses, there were no significant differences in long-term outcomes between income levels. CONCLUSION: Low educational level is strongly associated with worse long-term outcomes after injury. However, although household income is associated with long-term outcomes, it matters where the threshold is. The impact of different socioeconomic measures on long-term outcomes after trauma cannot be assumed to be interchangeable. LEVEL OF EVIDENCE: Prognostic and epidemiological, level III.