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The following is a summary of “Sex and 30-day survival following out-of-hospital cardiac arrest in Scotland 2011–2020,” published in the October 2024 issue of Emergency Medicine by Bijman et al. 

Males have a higher 30-day survival rate after out-of-hospital cardiac arrest (OHCA) than females, but factors beyond biological sex likely influence this difference.  

Researchers conducted a retrospective study to analyze the role of potential mediating factors in the association between sex and 30-day survival following OHCA in Scotland. 

They primarily focused on adult OHCA cases not witnessed by emergency medical services (EMS). The analysis included all incidents across Scotland where the Scottish Ambulance Service (SAS) attempted resuscitation between April 1, 2011, and March 1, 2020. Logistic regression was applied to assess the influence of factors such as age, socioeconomic status, urban-rural location, initial cardiac rhythm, bystander cardiopulmonary resuscitation (CPR), and the arrest location (either at home or away).  

The results showed 20,585 OHCA cases, with 13,130 males and 7,455 females. The median age for males was 69 years (interquartile range [IQR], 22), while for females it was 72 years (IQR, 23). A higher percentage of males presented with an initial shockable rhythm (29.4% vs. 12.4%) and received bystander CPR (56.7% vs. 53.2%) compared to females. More females experienced OHCA at home (78.8% vs 66.8%), and 30-day survival was higher among males than females (8.2% vs 6.2%). Males also had higher age-adjusted odds of 30-day survival compared to females (odds ratio [OR], 1.26; 95% confidence interval [CI], 1.12–1.41). Mediation analysis indicated that initial cardiac rhythm and arrest location contributed to the outcome.  

They concluded that the higher 30-day survival in males after OHCA was mediated by an initial cardiac rhythm and arrest location, with no direct association between sex and survival after adjusting for these variables. 

Source: intjem.biomedcentral.com/articles/10.1186/s12245-024-00731-0