A Population-based Analysis of Neighborhood Socioeconomic Status and Injury Admission Rates and In-hospital Mortality

Background: Research indicates that neighborhood socioeconomic status (N-SES) is inversely related to injury and injury-related mortality. We hypothesized that injury-related hospitalization rates would vary by N-SES and that N-SES would be related to in-hospital mortality.

Study Design: Adults (age 18 to 84 years) living in Shelby County, TN, were eligible for the study. Addresses of adults admitted to the only Level I trauma center in the county from 1996 to 2005 were geocoded and matched to 1 of 214 census tract groups. Census tract groups were divided into quintiles based on percent of the population living below the poverty level (lowest to highest income N-SES). Crude injury admission rate ratios (CIRR) and 95% confidence intervals (CI) were calculated. Multivariable logistic regression was used to determine if N-SES was associated with in-hospital mortality.

Results: Compared with the highest N-SES, those in the lowest N-SES suffered significantly higher rates of blunt (CIRR 5.74; 95% CI 5.35, 6.15) and penetrating injuries (CIRR 20.98; 95% CI 18.03, 24.42). On multivariable logistic regression analysis, compared with the highest N-SES, decreasing N-SES was not associated with in-hospital mortality for blunt (high-middle [0.90; 95% CI 0.57, 1.44]; middle [1.22; 95% CI 0.78, 1.87]; low-middle [0.89; 95% CI 0.58, 1.39]; lowest [0.67; 95% CI 0.42, 1.08]); or penetrating injury (high-middle [1.35; 95% CI 0.48, 3.81]; middle [2.77; 95% CI 0.99, 7.25]; low-middle [1.44; 95% CI 0.55, 3.74]; and lowest [1.03; 95% CI 0.39, 2.73]).

Conclusions: N-SES was inversely related to crude injury rates for all mechanisms. However, in-hospital mortality was not associated with N-SES level.