Incidence and Risk Factor Analysis of Thromboembolic Events in East Asian Patients With Inflammatory Bowel Disease, a Multinational Collaborative Study.

Background: Inflammatory bowel disease (IBD) increases the risk of venous thromboembolism (VTE) events. However, the incidence and necessity of prophylaxis for VTE in Asian IBD patients is unknown. We examined the incidence of VTE in East Asian IBD patients and analyze the possible risk factors.

Methods: We conducted a multinational retrospective study of 2562 hospitalized IBD patients from 2010 to 2015. Moreover, a nationwide cohort study from 2001 to 2013 from the Taiwan National Health Insurance Research Database (NHIRD) was conducted to analyze the incidence rate of VTE in IBD and non-IBD patients.

Results: In the hospitalized cohort, 24 IBD patients [17 ulcerative colitis (UC) and 7 Crohn's disease (CD)] received a VTE diagnosis (0.9%). These patients had a higher proportion of extensive UC (P = 0.04), penetrating-type CD (P < 0.01), and bowel operation history (P = 0.01). VTE was associated with low hemoglobin (P < 0.01), low platelet (P < 0.01), and low albumin (P < 0.01) levels. For the nation-wide cohort study, 3178 IBD patients and 31,780 age- and sex-matched non-IBD patients were analyzed. The average incidence rate was 1.15 per 1000 person-years in the IBD cohort and 0.51 in the non-IBD cohort. The relative risk was 2.27 (95% CI, 1.99-2.60).

Conclusions: East Asian IBD patients carry a 2-fold increased risk of VTE than the general population. The incidence of VTE in the East Asian IBD patients is still lower than that in Western countries. Therefore, close monitoring rather than routine prophylaxis of VTE in East Asian IBD patients is recommended.