OBJECTIVE: To identify prognostic factors for the development of venous thromboembolism in the ICU.
DATA SOURCES: We searched MEDLINE, EMBASE, and Cochrane CENTRAL from inception to March 1, 2021.
STUDY SELECTION: We included English-language studies describing prognostic factors associated with the development of venous thromboembolism among critically ill patients.
DATA EXTRACTION: Two authors performed data extraction and risk-of-bias assessment. We pooled adjusted odds ratios and adjusted hazard ratios for prognostic factors using random-effects model. We assessed risk of bias using the Quality in Prognosis Studies tool and certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluations approach.
DATA SYNTHESIS: We included 39 observational cohort studies involving 729,477 patients. Patient factors with high or moderate certainty of association with increased odds of venous thromboembolism include older age (adjusted odds ratio, 1.15; 95% CI, 1.02-1.29 per 10 yr), obesity (adjusted odds ratio, 1.25; 95% CI, 1.18-1.32), active malignancy (adjusted odds ratio, 1.70; 95% CI, 1.18-2.44), history of venous thromboembolism (adjusted odds ratio, 4.77; 95% CI, 3.42-6.65), and history of recent surgery (adjusted odds ratio, 1.77; 95% CI, 1.26-2.47). ICU-specific factors with high or moderate certainty of association with increased risk of venous thromboembolism include sepsis (adjusted odds ratio, 1.41; 95% CI, 1.12-1.78), lack of pharmacologic venous thromboembolism prophylaxis (adjusted odds ratio, 1.80; 95% CI, 1.14-2.84), central venous catheter (adjusted odds ratio, 2.93; 95% CI, 1.98-4.34), invasive mechanical ventilation (adjusted odds ratio, 1.74; 95% CI, 1.36-2.24), and use of vasoactive medication (adjusted odds ratio, 1.86; 95% CI, 1.23-2.81).
CONCLUSIONS: This meta-analysis provides quantitative summaries of the association between patient-specific and ICU-related prognostic factors and the risk of venous thromboembolism in the ICU. These findings provide the foundation for the development of a venous thromboembolism risk stratification tool for critically ill patients.