Socio-economic position and sudden cardiac death: a Danish nationwide study

The aim of this study was to examine differences in incidence rates of all-cause mortality (ACM) and sudden cardiac death (SCD) in persons of differing socio-economic position (SEP).

All deaths in Denmark from 1 January to 31 December 2010 (1 year) were included. Autopsy reports, death certificates, discharge summaries, and nationwide health registries were reviewed to identify cases of SCD. Socio-economic position was measured as either household income or highest achieved educational level and analysed separately. Hazard rates were calculated using univariate and multivariable Cox regression models adjusting for age, sex, and selected comorbidities. A total of 53 452 deaths were included, of which 6820 were classified as SCDs. Incidence rates of ACM and SCD increased with age and were higher in the lower SEP groups. The greatest difference in SCD incidence was found between the low and high education level groups, with an incidence rate ratio of 5.1 (95% confidence interval 3.8-6.8). The hazard ratios for ACM and SCD were significantly higher for low SEP groups, independent of comorbidities. Compared with the highest income group, the low-income group had adjusted hazard ratios of ACM and SCD that were 2.17 (2.01-2.34) and 1.72 (1.67-1.76), respectively.

We observed an inverse association between both income and education level and the risk of ACM and SCD in the general population, which persisted independently of baseline comorbidities. Our results indicate a need for further research into the mechanisms behind socio-economic disparities in healthcare and targeted preventative strategies.