Lower socioeconomic status is associated with increased long-term mortality after sudden cardiac arrest

Determinants of long-term survival after sudden cardiac arrest (SCA) are not fully elucidated. We investigated the impact of patients' socioeconomic status (SES) on long-term mortality in SCA survivors.

To investigate the association between SES, as estimated by median household income by zip code of residence, and long-term survival after SCA.

We analyzed the electronic medical records of patients who presented to our institution with SCA between 2000 and 2012 and were discharged alive. Patients were stratified into quartiles by median household income of their home zip code. Baseline characteristics of patients were compared by income quartiles. The impact of SES on mortality was assessed using a multivariable Cox proportional hazards model incorporating all unbalanced covariates.

Our cohort consisted of 1420 patients (mean age of 62 years; 41% men; 82% white). Over a 3.6-year median follow-up, 47% of patients died. After adjusting for unbalanced baseline covariates, patients in the poorest income quartile had a 25% increase in their risk of death compared to other SCA survivors (hazard ratios = 1.25, 95% confidence interval 1.00-1.56, P = .046).

In conclusion, lower SES is an independent predictor of long-term mortality in survivors of SCA. Designing interventions to improve survival after SCA requires attention to patients' social and economic factors.