Women have lower chances than men to be resuscitated and survive out-of-hospital cardiac arrest

Abstract

Aims: Previous studies on sex differences in out-of-hospital cardiac arrest (OHCA) had limited scope and yielded conflicting results. We aimed to provide a comprehensive overall view on sex differences in care utilization, and outcome of OHCA.

Methods and results: We performed a population-based cohort-study, analysing all emergency medical service (EMS) treated resuscitation attempts in one province of the Netherlands (2006-2012). We calculated odds ratios (ORs) for the association of sex and chance of a resuscitation attempt by EMS, shockable initial rhythm (SIR), and in-hospital treatment using logistic regression analysis. Additionally, we provided an overview of sex differences in overall survival and survival at successive stages of care, in the entire study population and in patients with SIR. We identified 5717 EMS-treated OHCAs (28.0% female). Women with OHCA were less likely than men to receive a resuscitation attempt by a bystander (67.9% vs. 72.7%; P < 0.001), even when OHCA was witnessed (69.2% vs. 73.9%; P < 0.001). Women who were resuscitated had lower odds than men for overall survival to hospital discharge [OR 0.57; 95% confidence interval (CI) 0.48-0.67; 12.5% vs. 20.1%; P < 0.001], survival from OHCA to hospital admission (OR 0.88; 95% CI 0.78-0.99; 33.6% vs. 36.6%; P = 0.033), and survival from hospital admission to discharge (OR 0.49, 95% CI 0.40-0.60; 33.1% vs. 51.7%). This was explained by a lower rate of SIR in women (33.7% vs. 52.7%; P < 0.001). After adjustment for resuscitation parameters, female sex remained independently associated with lower SIR rate.

Conclusion: In case of OHCA, women are less often resuscitated by bystanders than men. When resuscitation is attempted, women have lower survival rates at each successive stage of care. These sex gaps are likely explained by lower rate of SIR in women, which can only partly be explained by resuscitation characteristics.

Keywords: Cardiopulmonary resuscitation; ESCAPE-NET; Epidemiology; Out-of-hospital cardiac arrest; Sex differences.

Figure 1

Patient inclusion, 2006–2012. ARREST, Amsterdam Resuscitation Studies; DNAR, do not attempt to resuscitate; EMS, emergency medical service; ICD, implantable cardioverter-defibrillator.

Figure 2

An overview of sex differences in survival after out-of-hospital cardiac arrest. (A) Survival from out-of-hospital cardiac arrest to survival at hospital discharge in the entire study population. (B) Survival from out-of-hospital cardiac arrest to survival at hospital discharge in patients with witnessed out-of-hospital cardiac arrest and bystander cardiopulmonary resuscitation. (C) Survival from out-of-hospital cardiac arrest to survival at hospital discharge in patients with a shockable initial rhythm. (D) Survival from out-of-hospital cardiac arrest to hospital admission in the entire study population. (E) Survival from out-of-hospital cardiac arrest to hospital admission in patients with witnessed out-of-hospital cardiac arrest and bystander cardiopulmonary resuscitation. (F) Survival from out-of-hospital cardiac arrest to hospital admission in patients with a shockable initial rhythm. (G) Survival from hospital admission to hospital discharge in the entire study population. (H) Survival from hospital admission to hospital discharge in patients with witnessed out-of-hospital cardiac arrest and bystander cardiopulmonary resuscitation. (I) Survival from hospital admission to hospital discharge in patients with a shockable initial rhythm. ^†Limited to patients hospitalized with return of spontaneous circulation at any hospital ward. The bars represent the percentages of survival in patients suffering out-of-hospital cardiac arrest and resuscitated by emergency medical service personnel (numbers are presented in Supplementary material online, Table S4). Error bars denote 95% confidence intervals. N, number; OHCA, out-of-hospital cardiac arrest; SIR, shockable initial rhythm.

Take home figure

An overview of sex differences in survival after out-of-hospital cardiac arrest. (A) Survival from out-of-hospital cardiac arrest to survival at hospital discharge in the entire study population. (B) Survival from out-of-hospital cardiac arrest to survival at hospital discharge in patients with a shockable initial rhythm. (C) Survival from out-of-hospital cardiac arrest to hospital admission in the entire study population. (D) Survival from hospital admission to hospital discharge in the entire study population. ^†Limited to patients hospitalized with return of spontaneous circulation at any hospital ward. The bars represent the percentages of survival in patients suffering an out-of-hospital cardiac arrest and resuscitated by emergency medical service personnel. Error bars denote 95% confidence intervals. N, number; OHCA, out-of-hospital cardiac arrest; SIR, shockable initial rhythm.