Neighborhood Poverty Rate and Mortality in Patients Receiving Critical Care in the Academic Medical Center Setting

Background: Poverty is associated with increased risk of chronic illness but its contribution to critical care outcome is not well defined. Methods: We performed a multicenter observational study of 38,917 patients, aged 18 years, who received critical care between 1997 and 2007. The patients were treated in two academic medical centers in Boston, Massachusetts. Data sources included 1990 US census and hospital administrative data. The exposure of interest was neighborhood poverty rate, categorized as < 5%, 5% to 10%, 10% to 20%, 20% to 40% and >40%. Neighborhood poverty rate is the percentage of residents below the federal poverty line. Census tracts were used as the geographic units of analysis. Logistic regression examined death by days 30, 90, and 365 post-critical care initiation and in-hospital mortality. Adjusted ORs were estimated by multivariable logistic regression models. Sensitivity analysis was performed for 1-year postdischarge mortality among patients discharged to home. Results: Following multivariable adjustment, neighborhood poverty rate was not associated with all-cause 30-day mortality: 5% to 10% OR, 1.05 (95% CI, 0.98-1.14; P =.2); 10% to 20% OR, 0.96 (95% CI, 0.87-1.06; P =.5); 20% to 40% OR, 1.08 (95% CI, 0.96-1.22; P =.2); >40% OR, 1.20 (95% CI, 0.90-1.60; P =.2); referent in each is < 5%. Similar nonsignificant associations were noted at 90-day and 365-day mortality post-critical care initiation and in-hospital mortality. Among patients discharged to home, neighborhood poverty rate was not associated with 1-year-postdischarge mortality. Conclusions: Our study suggests that there is no relationship between the neighborhood poverty rate and mortality up to 1 year following critical care at academic medical centers. CHEST 2011;139(6):1368-1379