Objective Socioeconomic status (SES) has been linked to heart disease, but its influence on outcome from out-of-hospital cardiac arrest (OHCA) is not well understood. We hypothesized that higher levels of SES would be associated with better survival potentially through demographic, circumstance, or care factors.
Methods We conducted a cohort investigation of OHCA due to heart disease treated by emergency medical services between January 1, 1999 and December 31, 2003 in King County, Washington (n=1797). Socioeconomic status was assessed using 2 different measures: an individual-level measure, tax assessed property value per unit, and a geographic-based measure, median household income from the 2000 Census. We used logistic regression to evaluate the association between survival to hospital discharge and quartile of SES. Models systematically adjusted for demographic, circumstance, and care factors that could potentially confound the association.
Results Socioeconomic status as measured by value per unit was associated with survival in unadjusted models (Odds ratio [OR]=1.21 [1.05, 1.36] for each successive increase in value per unit quartile). Adjustment for demographic, circumstance, and care factors altered the association only slightly (fully-adjusted OR=1.23 [1.08, 1.39]). In contrast, SES as measured by median household income was not associated with survival in unadjusted or adjusted models. The results were consistent across subgroups defined by age, gender, and presenting rhythm.
Conclusion An individual-level but not area-level measure of SES predicted survival following OHCA independent of demographic, circumstance, or care factors. Future research should continue to investigate the mechanisms through which SES is associated with survival from OHCA.