Association between sex and mortality in adults with in-hospital and out-of-hospital cardiac arrest: A systematic review and meta-analysis

Objectives: Conflicting data exists regarding the association between sex and mortality in adults with in-hospital (IHCA) and out-of-hospital cardiac arrest (OHCA). We therefore conducted a meta-analysis to investigate the association between sex and mortality in adults with IHCA and OHCA. Methods: We systematically searched MEDLINE and Cochrane databases to identify studies reporting sex-specific mortality in adults following IHCA or OHCA from inception to April 2020. Data were pooled using random-effects models. The primary outcome of interest was in-hospital (or 30-day) all-cause mortality. Results: We included 21 observational studies with a total of 1,029,978 adult patients – 622,085 men and 407,893 women. Seven studies included patients only with IHCA and 14 studies included patients only with OHCA. Female sex was associated with significantly higher mortality following OHCA [odds ratio (OR) 1.56, 95% confidence interval (CI) 1.32–1.84, p < 0.001) and a trend toward higher mortality following IHCA (OR 1.10, 95%CI 1.00–1.20, p = 0.052). Conclusions: In adults with cardiac arrest, female sex was associated with significantly higher mortality following OHCA and a trend toward higher mortality following IHCA.