Impact of bystander and patient sex on cardiopulmonary resuscitation provision in out-of-hospital cardiac arrest

BACKGROUND: Female patients who experience out-of-hospital cardiac arrest (OHCA) are less likely to receive bystander cardiopulmonary resuscitation (CPR) than male patients. However, the interaction between the patient and the sex of the bystander in CPR provision remains underexplored. Therefore, this study aimed to investigate the interaction between patient and sex of bystander in CPR provision during OHCA and to assess CPR rates based on dispatcher-assisted CPR (DA-CPR) administration status. METHODS: This cohort study used prospectively collected nationwide registry data between January 2019 and June 2023. Adult patients with medical aetiology of OHCA who were transported by emergency medical services were included. The primary outcome was bystander CPR provision according to sex. The secondary outcome was the provision of bystander CPR based on DA-CPR administration status. RESULTS: A total of 6487 patients with OHCA were included (median (IQR) age: 55 (52-64) years; male bystanders treated 3977 patients (61.3%)). The bystander CPR rate was lower when the patient and sex of bystander differed (male patient-male bystander, 85.0% vs male patient-female bystander, 79.2%; female patient-male bystander, 79.5% vs female patient-female bystander, 82.1%). Female bystanders were less likely to provide bystander CPR than male bystanders (adjusted OR (aOR): 0.83, 95% CI 0.73 to 0.95). The odds of a female bystander providing CPR to a male patient were significantly lower than those of a male bystander (aOR: 0.684, 95% CI 0.578 to 0.810). This difference was reduced when DA-CPR was administered (without DA-CPR, aOR: 0.673, 95% CI 0.475 to 0.952 vs with DA-CPR, aOR: 0.822, 95% CI 0.706 to 0.957). CONCLUSION: An interaction between the patient and the sex of bystander was observed, particularly when the patient was a male and the bystander was a female. DA-CPR may serve as a potential intervention to help mitigate this disparity.