Interaction between bystander sex and patient sex in bystander cardiopulmonary resuscitation for Out-of-Hospital cardiac arrests.

BACKGROUND

Bystander cardiopulmonary resuscitation (CPR) is a critical factor in improving out-of-hospital cardiac arrest (OHCA) survival. The aim of this study was to investigate the interaction effect of bystander sex and patient sex on the provision of bystander CPR.

METHODS

This was a retrospective cohort study using national OHCA registry in Korea. The inclusion criteria were adult bystander-witnessed OHCA patients with presumed cardiac etiology from January 2016 to December 2020. The primary outcome was the provision of bystander CPR. Multivariable logistic regression and interaction analysis were conducted to evaluate the impact of bystander sex on bystander CPR provision based on patient sex.

RESULTS

The study included 24,919 patients with OHCA, 58.2% with male-bystanders and 41.8% with female-bystanders. Female bystanders were less likely to perform bystander CPR than male bystanders (68.0% vs. 78.8%, adjusted OR (95% CI): 0.62 (0.58-0.66)). Among patients with CPR-trained bystanders, female bystanders had lower odds of bystander CPR (0.85 (0.73-0.97)). In the interaction analysis between bystander and patient sex, a significant difference was observed in the likelihood of bystander CPR according to the patient sex. Female bystanders had lower odds of bystander CPR than male bystanders for male patients (0.47 (0.43-0.50)). However, there were no significant differences between male and female bystanders for female patients (0.91 (0.88-1.07)).

CONCLUSION

Female bystanders have a lower likelihood of providing bystander CPR than male bystanders. Additionally, an interaction was observed between bystander sex and patient sex in the providing bystander CPR, with the association being more pronounced in male OHCA patients.