Sex specific differences in short-term mortality after ICU-delirium

Introduction Delirium is a frequent complication in critically ill patients and is associated with adverse outcomes such as long-term cognitive impairment and increased mortality. It is unknown whether there are sex-related differences in ICU-delirium and associated outcomes. We aimed to assess sex-specific differences in short-term mortality following ICU-delirium. Methods We conducted a retrospective cohort study using the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database. Adult ICU patients who were diagnosed with delirium using the Confusion Assessment Method for the ICU (CAM-ICU) or the Intensive Care Delirium Screening Checklist (ICDSC) were included. The primary outcome was 30-day mortality following delirium onset. To control for baseline differences in demographics, illness severity, and comorbidities, we applied 1:1 propensity score matching. Cox proportional hazards regression models were used to evaluate the association between sex and mortality. Results A total of 8950 ICU patients with delirium were analyzed, of whom 42.6% were female. In univariable analysis, women had higher crude mortality (26.0% vs. 23.4%; HR 1.16, 95% CI 1.071–1.267, p < 0.001). After propensity score matching, the cohort included 3811 females and 3811 males. Thirty-day mortality was again higher in women (HR 1.14, 95% CI 1.046–1.252; p = 0.003). Conclusion Our study suggests that women with ICU-delirium have a significantly higher risk of short-term mortality than men. Further research is needed to understand the biological and clinical factors driving this disparity and to inform sex-specific interventions for ICU-delirium.