Previous research suggests that limitations of life-sustaining treatment (LST) may be more common in women than men, but few studies have included data on clinical reasoning or limitation type. This study aimed to investigate sex differences in LST-limitations in the ICU and in their documented characteristics.

All adult (≥18 years) ICU patients registered in the Swedish Intensive Care Register between 2019 and 2024 were included. A multivariable logistic regression model, adjusted for SAPS3 and age, analysed the association between sex and LST-limitations. Limitation characteristics were compared using Chi-square test (categorical variables) and Wilcoxon rank-sum test (numeric variables).

The cohort included 111,354 patients; 41.7% women. LST-limitations occurred in 24.4% of patients and were more frequent in women than in men (25.3% vs. 23.8%, p < 0.0001). In adjusted analyses women had higher odds of receiving an LST-limitation than men, both in the full cohort (OR 1.21, 95% CI 1.17−1.25) and among 30-day non-survivors (OR 1.24, 95% CI 1.18−1.32). Women received LST-limitations earlier than men (2.8 h after admission vs 4.5 h, p < 0.0001). Acute disease and therapy failure were more often documented reasons in men than in women (78.8% vs 74.3%, p < 0.0001; 21.2% vs. 18.6%, p = 0.0001), whereas autonomy and chronic disease were more frequent in women (7.8% vs 5.9%, p < 0.0001; 63.2% vs. 60.7%, p = 0.0021). Women were more often involved in decision-making (13.3% vs 11.8%, p = 0.0074).

Women were more likely to receive LST-limitations and received them earlier. Men who died within 30 days were less likely to have had an LST-limitation than women. Documented reasons for LST-limitations differed by sex, and women had higher rates of documented patient involvement.