# Poster Session II - A275 PREDICTING RISK FOR VENOUS THROMBOEMBOLISM AFTER HOSPITAL DISCHARGE IN PATIENTS WITH INFLAMMATORY BOWEL DISEASE

## TL;DR

This study identifies risk factors for blood clots after hospital discharge in inflammatory bowel disease patients, aiming to help identify those needing extended prevention.

## Contribution

The study is the first to identify specific clinical predictors of post-discharge venous thromboembolism risk in inflammatory bowel disease patients.

## Key findings

- Five independent risk factors for VTE after discharge were identified: prior VTE, central venous catheter, cancer, low hemoglobin, and age over 45.
- Only 8.1% of discharges received extended thromboprophylaxis, suggesting a need for better risk stratification.
- The findings aim to inform a future multicenter prediction tool for post-discharge VTE risk in IBD patients.

## Abstract

Patients with inflammatory bowel disease (IBD) face an elevated risk of venous thromboembolism (VTE) during hospitalization. Emerging evidence suggests this risk may persist post-discharge, yet no validated tools exist to identify high-risk patients who may benefit from extended thromboprophylaxis.

To identify risk factors associated with risk of VTE among patients with IBD patients within 3 months following hospital discharge.

We performed at retrospective, matched case-control study at The Ottawa Hospital (2009-2024). Adults (>17 years) with pre-existing IBD who developed a VTE were identified by our institutional databases using validated ICD-10 codes, confirmed by chart review. Patients hospitalized ≥48 hours who developed a VTE within 3 months after hospital discharge (cases) were matched to 3 patients without post-dicharge VTE (controls) by discharge date. Candidate predictors were selected a priori based on literature review. Univariable analysis identified variables with p < 0.05. Next, multivariable conditional logistic regression with stratification by matched set was performed.

We identified 468 eligible hospital discharges, 117 eligible post-discharges were identified occurring within 3 months prior to a VTE event, matched to 351 controls (Table 1). Extended thromboprophylaxis was only given to 8.1% of discharges. Multivariable analysis identified five independent predictors (Figure 1): prior VTE (OR 5.60; 95% CI 2.95-10.62), central venous catheter during admission (OR 5.09; 2.14-12.07), cancer (past/current) (OR 3.41; 1.45-8.02), hemoglobin <100 g/L (OR 2.43; 1.32-4.46), and age >45 years (OR 2.32; 1.23-4.39) (all p < 0.01).

Descriptive statistics and univariable analysis of IBD patients with and without post-discharge VTE.

In this single-center retrospective study, we identified multiple clinical variables that are associated with VTE after hospital discharge in patients with IBD. This work will help to create a future multicenter clinical prediction tool to identify which patients with IBD have the highest risk of developing VTE after hospital discharge.

Ottawa Hospital Research Institute