Females are less likely to receive bystander cardiopulmonary resuscitation in witnessed out-of-hospital cardiac arrest: An Australian perspective
Authors: Munot Sonali , Bray Janet E , Redfern Julie , Bauman Adrian , Marschner Simone , Semsarian Christopher , Denniss Alan Robert , Coggins Andrew , Middleton Paul M , Jennings Garry , Angell Blake , Kumar Saurabh , Kovoor Pramesh , Vukasovic Matthew , Bendall Jason C , Evens T , Chow Clara K 
Published: December 2023

Background

Bystander cardiopulmonary resuscitation (CPR) plays a significant role in survival from out-of-hospital cardiac arrest (OHCA). This study aimed to assess whether bystander CPR differed by patient sex among bystander-witnessed arrests.

Methods

Data on all OHCAs attended by New South Wales (NSW) paramedics between January 2017 and December 2019 was obtained from the NSW Public Health Risks and Outcomes Registry (PHROR). This observational study was restricted to bystander-witnessed cases with presumed medical aetiology. OHCA from arrests in aged care, medical facilities, and cases with an advance care directive (do-not-resuscitate) were excluded. Multivariate logistic regression was used to examine the association of patient sex with bystander CPR. Secondary outcomes were OHCA recognition, bystander AED applied, initial shockable rhythm, and survival outcomes.

Results

Among the 4,491 bystander-witnessed cases, females were less likely to receive bystander CPR in both private residential (Adjusted Odds ratio [AOR]: 0.82, 95%CI: 0.70-0.95) and public locations (AOR: 0.58, 95%CI:0.39-0.88). Recognition of OHCA in the emergency call was lower for females, particularly in those who arrested in public locations (84.6% vs 91.6%-males, p=0.002) and it partially explained the association of sex with bystander CPR (∼44%). There was no significant difference in OHCA recognition by sex for arrests in private residential locations (p=0.2). Females had lower rates of bystander AED use (4.8% vs 9.6%, p<0.001) however, after adjustment for arrest location and other covariates, this relationship was attenuated and no longer significant (AOR: 0.83, 95%CI: 0.60-1.12). Females were significantly less likely to record an initial shockable rhythm (AOR: 0.52, 95%CI: 0.44-0.61). Although females had greater odds of event survival (AOR: 1.34, 95%CI: 1.15 – 1.56), there was no sex difference in survival to hospital discharge (AOR: 0.96, 95%CI: 0.77-1.19).

Conclusion

OHCA recognition and bystander CPR provision differs by patient sex in NSW. Given their importance to patient outcomes, research is needed to understand why this difference occurs and to raise awareness of this issue to the public.

CLINICAL PERSPECTIVE

What is new?

Female OHCA patients in New South Wales, Australia were less likely to receive bystander CPR, irrespective of arrest location.

In public locations, recognition of OHCA during the emergency call was lower in women and this partly explained the observed sex difference in bystander CPR provision.

What are the clinical implications?

Public education campaigns and training programs that address bystander response should consider sex differences as a potential barrier to bystander CPR in OHCA

Future research that examines reasons for lower rates of bystander response in women and ways of addressing this barrier could help address sex disparities in the future.