Risk of Venous Thromboembolism After Hospital Discharge in Patients With Inflammatory Bowel Disease: A Population-based Study

Background Inflammatory bowel disease (IBD) is associated with a high risk of venous thromboembolism (VTE) during hospitalization. It is unclear if this association persists after discharge. We aimed to assess the incidence of postdischarge VTE in IBD patients and to determine if IBD is associated with increased VTE risk. Methods We performed a population-based cohort study between 2002 and 2016 using Ontario health administrative data sets. Hospitalized (≥72 hours) adults with IBD were stratified into nonsurgical and surgical cohorts and matched on propensity score to non-IBD controls. Time to postdischarge VTE was assessed by Kaplan-Meier methods, and VTE risk was assessed by Cox proportional hazard models. Results A total of 81,900 IBD discharges (62,848 nonsurgical and 19,052 surgical) were matched to non-IBD controls. The cumulative incidence of VTE at 12 months after discharge was 2.3% for nonsurgical IBD patients and 1.6% for surgical IBD patients. The incidence increased in the nonsurgical IBD cohort by 4% per year (incidence rate ratio, 1.04; 95% CI, 1.02–1.05). In our propensity score-matched analysis, the risk of VTE at 1-month postdischarge was greater in nonsurgical IBD patients (hazard ratio [HR], 1.72; 95% CI, 1.51–1.96) and surgical patients with ulcerative colitis (HR, 1.68; 95% CI, 1.16–2.45) but not surgical patients with Crohn’s disease. These trends persisted through 12 months. Conclusions Nonsurgical IBD patients and surgical patients with ulcerative colitis are 1.7-fold more likely to develop postdischarge VTE than non-IBD patients. These findings support the need for increased vigilance and consideration of thromboprophylaxis in this population.