Association Between Sex and Clinical Outcomes for Critically Ill Patients in India: A Registry-Embedded Cohort Study

OBJECTIVES: To evaluate the association between sex assigned at birth and outcomes for critically ill patients in India. DESIGN: Retrospective registry-embedded cohort study. SETTING: Forty-five ICUs that are part of the Indian Registry of IntenSive care (IRIS). PATIENTS: We included adult (≥ 16 yr) patients admitted to ICUs in the IRIS. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary exposure was sex at birth, and the primary outcome was ICU mortality. Secondary outcomes included in-hospital mortality, receipt of mechanical ventilation, kidney replacement therapy, and vasopressors. Logistic regression models for the primary and secondary outcomes were adjusted for prespecified baseline covariates. We included 82,151 patients from 45 ICUs. Median (interquartile range) age was 60.0 years (45.0-70.0 yr) and 38.2% ( n = 31,409) of the cohort was female. Baseline characteristics were similar. Comparing sexes, ICU mortality (9.5% females vs. 10.3% males; adjusted odds ratio [adjOR], 0.95; 95% CI, 0.90-1.00; p = 0.07) and hospital mortality (19.4% vs. 20.8%; adjOR, 1.00; 95% CI, 0.97-1.03; p = 0.66) were similar. Females less commonly received invasive ventilation (22.2% vs. 26.3%; adjOR, 0.78; 95% CI, 0.75-0.82; p < 0.001), kidney replacement therapy (4.9% vs. 6.3%; adjOR, 0.73; 95% CI, 0.68-0.78; p < 0.001), and vasopressors (19.1% vs. 20.2%; adjOR, 0.95; 95% CI, 0.92-0.99; p = 0.03). In contrast, females more commonly received noninvasive ventilation (11.7% vs. 9.7%; odds ratio, 1.23; 95% CI, 1.18-1.30; p < 0.001). Results of the sensitivity analyses were consistent with the primary findings. CONCLUSIONS: In this registry-embedded cohort study, critically ill females less commonly received most types of organ supports, yet had similar adjusted ICU mortality compared with males.