Abstract
BACKGROUND: Conflicting data exist regarding sex-specific outcomes after cardiac arrest. This study investigates sex disparities in the provision of critical care and outcomes of in-hospital (IHCA) and out-of-hospital cardiac arrest (OHCA) patients. METHODS: Analysis of adult cardiac arrest patients admitted to certified Swiss intensive care units (ICUs) (01/2008-12/2022) using the nationwide prospective ICU registry. The primary outcome was ICU mortality, with secondary outcomes including ICU admission probability and advanced treatment provision. RESULTS: Among 41,733 individuals (34.9% women), 21,692 patients (30.6% women) were admitted to ICUs (16,571 OHCA patients/5121 IHCA patients). Women were less likely to be admitted to the ICU than men (incidence rate ratio 0.82 [95% CI 0.80-0.85] and had a higher ICU mortality (41.8% vs 36.2%; p < 0.001). Mortality differences were more pronounced in OHCA patients (unadjusted HR: 1.35 [95% CI 1.28-1.43]; adjusted HR: 1.19 [95% CI 1.12-1.25]). In IHCA patients, mortality differences were less pronounced (unadjusted HR: 1.14 [95% CI 1.04-1.25]) and vanished after adjustment for confounders: adjusted HR: 1.03 [95% CI 0.94-1.13]). Women after cardiac arrest were older, more severely ill, and received fewer interventions before (44.7% vs 54.0%; p < 0.001) and during ICU stay. A subgroup analysis of 11,202 patients revealed that treatment limitations were more frequent in women (46.7% vs 38.7%; p < 0.001). However, these limitations were associated with an increased risk of death in both sexes. CONCLUSIONS: This study highlights sex disparities in short-term mortality and ICU resource allocation among cardiac arrest patients, with women potentially facing disadvantages, in particular after OHCA. The limitations of ICU registry data, particularly the lack of detailed cardiac arrest-specific and comorbidity information, restrict definitive conclusions. Future research should prioritize prospective studies with more granular data to better understand and address these disparities.