Socioeconomic disparity in inpatient mortality after traumatic injury in adults

Background Prior studies have demonstrated that race and insurance status predict inpatient trauma mortality, but have been limited by their inability to adjust for direct measures of socioeconomic status (SES) and comorbidities. Our study aimed to identify whether a relationship exists between SES and inpatient trauma mortality after adjusting for known confounders. Methods Trauma patients aged 18-65 years with an Injury Severity Scores (ISS) of ≥9 were identified using the 2003-2009 Nationwide Inpatient Sample. Median household income (MHI) by zip code, available by quartiles, was used to measure SES. Multiple logistic regression analyses were performed to determine odds of inpatient mortality by MHI quartile, adjusting for ISS, type of injury, comorbidities, and patient demographics. Results In all, 267,621 patients met inclusion criteria. Patients in lower wealth quartiles had significantly greater unadjusted inpatient mortality compared with the wealthiest quartile. Adjusted odds of death were also higher compared with the wealthiest quartile for Q1 (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.06-1.20), Q2 (OR, 1.09; 95% CI, 1.02-1.17), and Q3 (OR, 1.11; 95% CI, 1.04-1.19). Conclusion MHI predicts inpatient mortality after adult trauma, even after adjusting for race, insurance status, and comorbidities. Efforts to mitigate trauma disparities should address SES as an independent predictor of outcomes.