Venous Thromboembolism Prophylaxis in Inflammatory Bowel Disease Inpatients: Systematic Review and Meta-Analysis.

Introduction: Inflammatory bowel disease (IBD) patients are three times more likely to develop venous thromboembolism (VTE), and guidelines recommend prophylaxis during all hospitalizations. In this systematic review, we sought to assess for the benefits and risks of VTE prophylaxis in hospitalized IBD patients.

Methods: We performed a systematic review and meta-analysis. We searched MEDLINE and others up to 2/2022, for studies on IBD inpatients treated with prophylactic anticoagulation during hospitalization, compared to no prophylaxis. Primary efficacy and safety outcomes were any VTE and major bleeding, respectively. Results were pooled using random-effects models, calculating odds ratios (OR), and 95% confidence intervals (CI). The ROBINS-I tool was used to assess bias.

Results: We extracted data from 18 observational studies and 2 randomized-trial subgroups. The studies were highly variable regarding the included populations, interventions, and outcome definitions. Meta-analysis of all studies showed a nonsignificant effect of prophylaxis on VTEs (OR: 0.97 [95% CI: 0.49-1.95]). An analysis of eight lower-risk-of-bias studies showed a significant reduction in VTEs (OR: 0.27 [95% CI: 0.13-0.55], number needed to treat (NNT) 34.8 [95% CI: 26.8-49.8]). A significant protective effect persisted in several subgroups. Major bleeding was reported in three studies and showed a significant increase with prophylaxis (OR: 2.02 [95% CI: 1.11-3.67], number needed to harm (NNH) 113.6 [95% CI: 40.7-very-large-number]).

Conclusion: In studies with lower-risk-of-bias, a significant reduction in VTEs was shown in patients treated with VTE prophylaxis (NNT = 35), which should be carefully considered against an increased major-bleeding risk (NNH = 114). However, current data are limited and randomized trials dedicated to IBD inpatients would aid in understating whether universal prophylaxis should be recommended.