P799 Use of anti-TNF agents may reduce a risk of venous thromboembolism in Korean patients with inflammatory bowel disease: A nationwide population-based study from the National Health Insurance Database
Abstract Background Inflammatory bowel disease (IBD) has a risk of venous thromboembolism (VTE) compared with healthy controls, which justify prophylaxis in practice. There are few data on VTE in Asian IBD patients including Koreans. We aimed to investigate the incidence of VTE and the potential risk factors in Korean IBD patients. Methods A nationwide population-based cohort study was performed using claims data from the National Health Insurance service in Korea for 10 years, from 2006 to 2015. VTE, Crohn’s disease (CD) and ulcerative colitis (UC) were operationally defined by using ICD-10 codes, codes for Rare and Intractable Diseases registration, and pharmaceutical prescriptions for IBD-specific drugs. Control group was defined as age- and sex-matched health insurance subscribers without IBD for the same period. The hazard ratio (HR) for the risk of VTE was calculated after adjusting for covariates such as age, sex, rural area, comorbidities, Charlson Comorbidity Index (CCI), admission, and therapeutic drugs use for IBD using multivariate Cox proportional hazard regression. Results A total of 45,037 patients were diagnosed with IBD (13,850 CD and 31,187 UC), and 133,019 were defined as controls. VTE occurred in 411 (0.91%) in IBD, 106 (0.76%) in CD, and 305 (0.98%) in UC, whereas 641 (0.48%) in controls. In univariate analysis among IBD patients, old age (>59 years: HR = 6.256), female sex (HR = 1.537), low income (HR = 1.3090), high CCI (>3 score: HR = 4.053), steroid use (HR = 1.872), emergency care (HR = 1.513) and hospitalisation (HR = 1.352) significantly increased a risk of VTE. However, anti-TNF agent use (HR = 0.611) significantly decreased a risk of VTE. In multivariate analysis with adjustment among all subjects, CD (HR = 15.833) and UC (HR = 8.125) significantly increased a risk of VTE compared with controls. Conclusion Our study demonstrates that VTE is significantly high in Korean IBD patients compared with controls. In addition, old age, female sex, low income, high CCI, steroid use, emergency care, and hospitalisation are suggested as risk factors of VTE in IBD. Interestingly, use of anti-TNF agents may reduce risk of VTE, which should be considered for prophylaxis strategy suitable for Korean IBD patients.