• global burden of disease
• education
• medical
• ventricular fibrillation

Sudden cardiac death (SCD) is a leading cause of death, being responsible for up to one in five deaths in Western countries. It can be described as an unexpected death due to a cardiovascular cause, with coronary heart disease being the most common underlying aetiology. In spite of improvements in the treatment and prevention of SCD, the rate of survival following its occurrence is still low. Therefore, SCD remains a large burden globally.1 This burden, however, is unequally distributed among the population. For instance, it has been found that people of low socioeconomic status have a higher incidence rate of SCD than people of high socioeconomic status.2 A good understanding of the socioeconomic disparities with regard to the incidence and outcomes of SCD is essential if we strive to effectively reduce its burden on society.

In the study in this issue of Heart, Møller et al investigated the effect of socioeconomic status on survival after out-of-hospital cardiac arrest (OHCA). Additionally, they sought to determine whether this effect is mediated by differences in rates of bystander cardiopulmonary resuscitation (CPR) across levels of socioeconomic status. They included all 21 480 patients who had OHCA from the Danish Cardiac Arrest Registry from 2001 to 2014 above 30 years of age and divided them into quartiles based on their income. What they found was that the patients with the highest incomes had up to 26% higher survival rates than those with the lowest incomes. They also found that patients with higher incomes had higher chances of bystander CPR. What was surprising, however, is that most of the income disparity in survival was not due to the difference in chances of bystander CPR. In fact, the latter only accounted for less than …