Missed Venous Thromboembolism Prophylaxis in ICU Patients: A Retrospective Cohort Study Using the Medical Information Mart for Intensive Care IV (MIMIC-IV)

INTRODUCTION: Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a preventable complication that significantly contributes to morbidity and mortality in intensive care unit (ICU) patients. Despite established guidelines recommending routine prophylaxis, many ICU patients do not receive the indicated doses. METHODS: We conducted a retrospective cohort study using the Medical Information Mart for Intensive Care IV (MIMIC-IV), a publicly available critical care database. Adult patients with a single ICU admission were stratified by receipt of pharmacologic VTE prophylaxis (subcutaneous heparin or enoxaparin). Primary outcomes were ICU length of stay (LOS) and in-hospital mortality. We performed t-tests, chi-square tests, and multivariable logistic regression, adjusting for age, gender, and emergency admission status. RESULTS: Among 65,355 ICU patients, 85.6% received pharmacologic prophylaxis. Patients who missed prophylaxis had significantly shorter ICU LOS (1.80 vs. 3.80 days, p < 0.001) but higher in-hospital mortality (17.1% vs. 11.6%, p < 0.001). Prophylaxis was associated with a 65% reduction in the adjusted odds of in-hospital death (OR: 0.35; 95% CI: 0.34-0.37). CONCLUSIONS: Missed VTE prophylaxis in ICU patients was associated with an increased in-hospital mortality. These findings support ICU quality improvement initiatives aimed at standardizing prophylaxis protocols to reduce preventable harm.