Gender differences and survival after an out-of-hospital cardiac arrest: a systematic review and meta-analysis

Patients who experience out-of-hospital cardiac arrest (OHCA) have unacceptably high mortality rates. It remains unclear whether gender has an association with survival in this regard. Hence, we aimed to investigate the association between gender and survival by conducting a systematic review and meta-analysis. The databases of PubMed, Embase, and Cochrane Database of Systematic Reviews were searched from inception to 17 March, 2020. Studies assessing the association between gender and survival to discharge or 30-day survival after OHCA were included. Two reviewers independently assessed the eligibility of the identified studies. The random-effects model was used to pool data, and the outcome was reported as odds ratios (ORs) and 95% confidence intervals, as the relative measure of association. Twenty-three eligible studies enrolling 897,805 patients were included in this systematic review. Overall, women were older and less likely to experience arrest in public places. When arrest occurred, women had less initial shockable rhythm, were less likely to be witnessed by bystanders, and were less likely provided with CPR compared with men. After admission, women underwent less coronary angiography, percutaneous coronary angiography, and targeted temperature management therapy. Eleven studies with ORs were pooled, showing a significant survival benefit in women (OR = 1.08, p < 0.05, I 2 = 52.3%). In the subgroup analysis, both premenopausal women (< 50 years) (OR = 1.42, p < 0.001, I 2 = 0%) and postmenopausal women (≥ 50 years) (OR = 1.07, p < 0.05, I 2 = 16.4%) had higher odds of survival compared with age-matched men. Despite the unfavorable factors, the pooled results showed a significant survival benefit in women after OHCA, especially in premenopausal women.