Venous thromboembolism and chronic venous disease among people who inject drugs: A systematic review and meta-analysis

Intravenous drug use continues to pose a substantial burden worldwide and little is known about the risk of venous thromboembolism (VTE) and its sequelae in people who inject drugs (PWID). A systematic literature search was conducted on the prevalence of VTE and chronic venous disease in intravenous drug users, as well as on the prevalence of intravenous drug use among selected VTE patients. Two reviewers independently selected the articles and appraised their quality. A random-effect meta-analysis was performed to pool risks across studies. We included 18 studies with a total of 7691 patients. The overall prevalence of VTE among PWID was 29% (95%CI: 19–40%). Among patients diagnosed with VTE, 15% (95%CI: 10–20%) were PWID. Similar rates were confirmed in more recent studies published in the past decade, although these studies are often based on the general population from higher-risk areas. Reported rates of chronic venous disease ranged between 58% and 61%. The majority of the included studies had a low to moderate quality of evidence. We could not exclude a selection bias in the studies in geographical regions with high intravenous drug use prevalence. VTE and chronic venous disease appear to be common and understudied complications of injective drug use. National programs for PWID patients should also focus on early and late VTE-associated complications.