Risk factors of venous thromboembolism in ICU patients: a systematic review and meta-analysis

Objective This study aimed to identify risk factors associated with the development of VTE in patients admitted to the intensive care unit (ICU).Methods A systematic literature search was conducted via PubMed, Embase, Web of Science, and Cochrane databases up to 25 April 2025, to identify studies examining the association between risk factors and the occurrence of venous thromboembolism (VTE) in ICU patients. Data were pooled using odds ratios (ORs) and 95% confidence intervals (CIs).Results A total of 2465 relevant studies were identified through the systematic search, of which 30 were included in the meta-analysis. The pooled data showed that the following were significant risk factors for venous thromboembolism (VTE) in ICU patients: central venous catheterization (OR = 2.67, 95% CI: 1.67–4.28; I2 = 28%), invasive mechanical ventilation (OR = 2.08, 95% CI: 1.46–2.96; I2 = 0%), advanced age (OR = 2.06, 95% CI: 1.28–3.31; I2 = 86%), length of ICU stay (OR = 4.24, 95% CI: 1.43–12.57; I2 = 98%), malignancy (OR = 2.30, 95% CI: 1.03–5.12; I2 = 67%), elevated D-dimer levels (OR = 2.46, 95% CI: 1.37–4.40; I2 = 34%), and a history of VTE (OR = 2.84, 95% CI: 1.45–5.55; I2 = 51%). According to the GRADE assessment, the quality of evidence was rated as moderate for invasive mechanical ventilation, low for central venous catheterization and D-dimer levels, and very low for the remaining factors.Conclusion Invasive mechanical ventilation, central venous catheterization, and elevated D-dimer levels are associated with VTE risk, supported by relatively high-quality evidence. These findings may help identify ICU patients at higher risk of VTE, inform the development of risk assessment models for patient stratification, and ultimately contribute to improved prognosis through optimal screening and management strategies.