Abstract
BACKGROUND: The impact of the sex of bystanders who initiate cardiopulmonary resuscitation (CPR) on out-of-hospital cardiac arrest (OHCA) patients has not been fully elucidated. This study aims to investigate the association between the sex of bystanders who perform CPR and the clinical outcomes of OHCA patients in real-world clinical settings. METHODS: We conducted a retrospective, observational study using data from the Okayama City Fire Department in Japan. Patients were categorized based on bystanders' sex. Our primary outcomes were return of spontaneous circulation (ROSC). Our secondary outcome was 30-day survival and 30-day favorable neurological outcome, defined as Cerebral Performance Category score of 1 or 2. Multivariable logistic regression analysis was used to examine the association between these groups and outcomes. RESULTS: The study included 3,209 patients with a comparable distribution of male (1,540 patients: 48.0%) and female bystanders (1,669 patients: 52.0%) between the groups. Overall, 221 (6.9%) ROSC at hospital arrival, 226 (7.0%) patients had 30-day survival, and 121 (3.8%) patients had 30-day favorable neurological outcomes. Bystander sex (female as reference) did not contribute to ROSC at hospital arrival (adjusted OR [aOR] 1.11, 95% CI: 0.76-1.61), 30-day survival (aOR 1.23, 95% CI: 0.83-1.82), or 30-day favorable neurological outcomes (aOR 0.66, 95% CI: 0.34-1.27). Basic life support education experience was a bystander factor positively associated with ROSC. Patient factors positively associated with ROSC were initial shockable rhythm and witness of cardiac arrest. CONCLUSION: There were no differences in ROSC, 30-day survival, or 30-day neurological outcomes in OHCA patients based on bystander sex.