Sex and out-of-hospital cardiac arrest survival: a systematic review

Abstract

Background The literature is unresolved on whether female receive advanced cardiac life support less than do male and on whether female have a survival advantage over male after cardiopulmonary resuscitation. Methods We systematically searched PubMed, Embase and Web of Science databases (from inception to 23-April-2022) for papers reporting outcomes in adult male and female after out-of-hospital cardiac arrest. The main study outcome was the rate of adjusted survival to hospital discharge or 30 days. Secondary outcomes included unadjusted survival to hospital discharge and favourable neurological outcome. Results A total of 28 studies were included, involving 1,931,123 patients. Female were older than male, their cardiac arrests were less likely to be witnessed and less likely to present with a shockable rhythm. Unadjusted analysis showed that females had a lower likelihood of survival than males (OR 0.68 [0.62–0.74], I2 = 97%). After adjustment, no significant difference was identified between male and female in survival at hospital discharge/30 days (OR 1.01 [0.93–1.11], I2 = 87%). Data showed that male had a significantly higher likelihood of favorable neurological outcome in unadjusted analysis but this trend disappeared after adjustment. Both the primary outcome (adjusted for several variables) and the secondary outcomes were associated with substantial heterogeneity. The variables examined using meta-regression, subgroup and sensitivity analyses (i.e., study type, location, years, population, quality of adjustment, risk of bias) did not reduce heterogeneity. Conclusions The adjusted rate of survival to hospital discharge/30 days was similar for male and female despite an initial seeming survival advantage for male. The validity of this finding is limited by substantial heterogeneity despite in-depth investigation of its causes, which raises concerns regarding latent inequalities in some reports nonetheless. Further study on this topic may require inclusion of factors not reported in the Utstein template and in-depth analysis of decision-making processes.

Gender disparities in patients undergoing extracorporeal cardiopulmonary resuscitation

“…Taking into account the higher rates of pulmonary embolism in female gender, this finding suggests that there might be considerable gender-specific differences in the events causing OHCA, calling for an individualised approach. These findings are consistent with the data from recent meta-analyses stating lower rates of acute coronary events as CA aetiology in female patients ( 9 , 17 ), as well as observational studies showing an overall lower prevalence and delayed incidence of cardiovascular atherosclerotic disease in female patients ( 20 , 21 ). Considering the higher rates of beneficial outcome in female patients, our data provide a reason to consider VA-ECMO as a therapy option for pulmonary embolism deteriorating to CA, supporting the present findings suggesting that this might be a feasible therapeutic strategy ( 22 ).…”

Epidemiology and outcome of out‐of‐hospital cardiac arrest in Salt Lake City: Sex‐based investigations

“…Our multivariable analysis findings, indicating no significant association between sex and survival outcomes, are consistent with the results of recent systematic reviews and meta‐analyses, 34 , 38 as well as other observational studies. 12 , 13 However, they are not in line with other studies suggesting an females have higher odds of survival, 23 , 39 and others indicating females have lower odds of survival.…”

Low-dose intravenous immunoglobulin for children with newly diagnosed immune thrombocytopenia: protocol of a systematic review and meta-analysis

“…If p>0.1 and I² <50%, the heterogeneity will be considered acceptable and the fixed-effect model will be adopted for meta-analysis. If p≤0.1 and I 2 ≥50%, the heterogeneity will be considered significant and the random-effect model will be adopted 32. Furthermore, we will actively explore the sources of heterogeneity from aspects of study design and quality through subgroup analysis and sensitivity analysis.…”