Venous thromboembolism associated with infections: a systematic review and meta-analysis

Venous thromboembolism (VTE) is a disease with complex pathophysiology and a significant cause of morbidity and mortality. Infections have been associated with VTE, but the synthesis of the incidence and strength of this association has not been performed.

A systematic review and meta-analysis were conducted to evaluate the association between infections and VTE. We excluded studies assessing the relationship between VTE and local skin infections, postpartum, malignancies, hypercoagulability syndromes, as well as studies that focused explicitly on orthopedic patients, COVID-19, HIV, and cytomegalovirus.

Twenty-one studies were included with 3 distinct study designs: 8 case-control, 3 case-crossover, and 10 retrospective cohort studies. 20/21 studies reported a statistically significant increase in VTE incidence among patients with infections compared to patients without infection. Subgroup meta-analyses for each study design showed strong associations: case-control studies [OR 3.35 (95 % CI 2.34-4.79)], case-crossover studies [OR 5.81 (95 % CI 2.12-15.89)], and retrospective cohort studies [OR 2.69 (95 % CI 1.90-3.80)]. The association between infection and VTE was consistent across subgroup meta-analyses, based on the time interval studied, clinical setting, or infection site. Additionally, there was a statistically significant association between bacterial infection and VTE [OR 2.81 (95 % CI: 1.73-4.57)]. None of the studies demonstrated a high risk of bias.

This meta-analysis showed a consistent association between infections and VTE, which is, at least partially, overlooked by the relevant risk assessment scores. Future research should focus on large, prospective studies to evaluate the effectiveness and safety of preventive anticoagulant treatment for patients with infectious diseases.