Inpatient and post-discharge thromboembolic events in inflammatory bowel disease patients: a 13 year retrospective cohort study at a tertiary Centre

Patients with inflammatory bowel disease (IBD) are at increased risk of thromboembolic events (TEEs), particularly during hospitalisation. While extended thromboprophylaxis is standard in the post-partum and the post-surgical settings, its employment in IBD patients is uncommon. Current international guidelines recommend that extended outpatient prophylaxis is considered only for high-risk post-discharge ambulatory IBD patients. To determine the incidence of inpatient and post-discharge TEEs in hospitalised IBD patients over a 13-year period and to identify associated risk factors.

We conducted a retrospective cohort study at a tertiary centre using hospital inpatient coding (HIPE) and radiology databases from 2012-2024. Discharges with a primary or secondary IBD diagnosis were cross-referenced with TEE-related imaging studies during admission and within 180 days post-discharge. Logistic regression was used to evaluate the associations between patient factors and TEEs.

Among 1,601 discharges involving 954 individual patients (54% female; median age 44 [IQR: 32-59]), 117 admissions (7.3%) had TEE-directed imaging. Ten inpatient TEEs were identified (0.6%). Age ≥50 years was significantly associated with inpatient TEE (OR: 6.3; 95% CI: 1.57-41.82; p = 0.02). Male gender, ulcerative colitis subtype, and inpatient surgery were not significant predictors. Post-discharge imaging within 180 days occurred in 63 discharges (3.9%), with six post-discharge TEEs detected (0.4%). No significant predictors of post-discharge TEE were identified.

Both inpatient and post-discharge TEEs were infrequent in hospitalised IBD patients. These findings do not support routine use of extended thromboprophylaxis after discharge in unselected patients. A risk-stratified approach remains appropriate pending further prospective data.