Gender effect in survival after out-of-hospital cardiac arrest: A nationwide, population-based, case-control propensity score matched study based Korean national cardiac arrest registry

Abstract

Objective This study aimed to describe the relationship between sex and survival of patients with out-of-hospital cardiac arrest (OHCA) and further investigate the potential impact of female reproductive hormones on survival outcomes, by stratifying the patients into two age groups. Methods This retrospective, national population-based observational, case-control study, included Korean OHCA data from January 1, 2009, to December 31, 2016. We used multiple logistic regression with propensity score-matched data. The primary outcome was survival-to-discharge. Results Of the 94,160 patients with OHCA included, 34.2% were women. Before propensity score matching (PSM), the survival-to-discharge rate was 5.2% for females and 9.1% for males, in the entire group (OR 0.556, 95% CI [–0.526–0.588], P<0.001). In the reproductive age group (age 18–44 years), the survival-to-discharge rate was 14% for females and 15.6% for males (OR 0.879, 95% CI [0.765–1.012], P = 0,072) and in the post-menopause age group (age ≥ 55 years), the survival-to-discharge rate was 4.1% for females and 7% for males (OR 0.562, 95% CI [0.524–0.603], P<0.001). After PSM (28,577 patients of each sex), the survival-to-discharge rate was 5.4% for females and 5.4% for males (OR, 1.009 [0.938–1.085], P = 0.810). In the reproductive age group, the survival-to-discharge rate was 14.5% for females and 11.5% for males (OR 1.306, 95% CI [1.079–1.580], P = 0.006) and in the post-menopause age group, the survival-to-discharge rate was 4.2% for females and 4.6% for males (OR 0.904, 95% CI [0.828–0.986], P = 0.022). After adjustment for confounders, women of reproductive age were more likely to survive at hospital discharge. However, there was no statistically significant difference in neurological outcome (OR 1.238, 95% CI [0.979–1.566], P = 0.074). Conclusions Females of reproductive age had a better chance of survival when matched for confounding factors. Further studies using sex hormones are needed to improve the survival rate of patients with OHCA.

The impact of patient sex on survival after unintentional trauma in Korea: a retrospective, observational, case-control study

“…Another possibility is that the protective effect of estrogen is present for only a brief period after a stressful event. Choi et al [ 24 ] assessed differences in survival among male and female patients after OHCA and concluded that women in the reproductive age group had a better chance of survival than men. Their conclusion is consistent with the findings of Deitch et al [ 20 ] and McKinley et al [ 21 ], who speculated that the initial protective effect of elevated estrogen decreased with time from the initial injury.…”

Gender disparities in patients undergoing extracorporeal cardiopulmonary resuscitation

“…All p-values were two-sided, and a p-value < 0.05 was considered significant. All Springer et al 10.3389/fcvm.2023.1265978 calculations were performed using the statistical analysis software R (R Core Team, 2023).…”

“…Studies have suggested that women exhibit overall lower survival rates and worse neurological outcomes after conventional CPR for CA compared with men (7)(8)(9). When analysing women of reproductive age, these effects seem to be suspended, with favourable outcomes reported in this collective (10). Whether these gender differences exist in the context of eCPR remains widely unknown, with only limited data available reporting inconsistent results (11,12).…”