Sex disparities in bystander defibrillation for out-of-hospital cardiac arrest

Abstract Background Previous studies have suggested that females experiencing out-of-hospital cardiac arrest (OHCA) receive lower rates of both bystander cardiopulmonary resuscitation (CPR) and defibrillation compared to males. Whether this disparity has improved over time is unknown. Purpose To investigate rates of bystander CPR and defibrillation in a sex-disaggregated manner over the last two decades. Methods A state-wide OHCA registry in Victoria, Australia collected data over twenty years (2002-2021) regarding rates of bystander interventions in OHCA. Characteristics and outcomes of each OHCA were compared with logistic regression according to sex and time (defined in two-year periods). Results 32,502 OHCAs were included (69.7% male). Both bystander CPR and defibrillation rates increased for females over time (p<0.0001). There was no sex disparity in receipt of bystander CPR after adjustment for baseline differences. Females were less likely than males to receive bystander defibrillation, with sex disparity increasing from 2010 onwards (adjOR 0.26 (95%CI 0.09-0.80) in 2020-21 for females compared to males). Conclusion Initiatives to increase bystander CPR and defibrillation have resulted in higher overall rates of bystander interventions in the last two decades and no significant sex differences in provision of bystander CPR. However, females receive less bystander defibrillation than males, and sex disparity is increasing. Strategies to promote bystander defibrillation in females experiencing OHCA with a shockable rhythm should be a priority.