Survival after out-of-hospital cardiac arrest is associated with area-level socioeconomic status

OBJECTIVE: Out-of-hospital cardiac arrest (OHCA) is a major cause of death in the Western world. In this study we aimed to investigate the relationship between area-level socioeconomic status (SES) and 30-day survival after OHCA. We hypothesised that high SES at an area level is associated with an improved chance of 30-day survival. METHODS: Patients with OHCA in Stockholm County between 1 January 2006 and 31 December 2015 were analysed retrospectively. To quantify area-level SES, we linked the patient's home address to 250 × 250/1000 × 1000 meter grids with aggregated information about income and education. We constructed multivariable logistic regression models in which area-level SES measures were adjusted for age, sex, emergency medical services response time, witnessed status, initial rhythm, aetiology, location and year of cardiac arrest. RESULTS: We included 7431 OHCAs. There was significantly greater 30-day survival (p=0.003) in areas with a high proportion of university-educated people. No statistically significant association was seen between median disposable income and 30-day survival. The adjusted OR for 30-day survival among patients in the highest educational quintile was 1.70 (95% CI 1.15 to 2.51) compared with patients in the lowest educational quintile. We found no significant interaction for sex. Positive trend with increasing area-level education was seen in both men and women but the trend was only statistically significant among men (p=0.012) CONCLUSIONS: Survival to 30 days after OHCA is positively associated with the average educational level of the residential area. Area-level income does not independently predict 30-day survival after OHCA.