Risk of Venous Thromboembolism After Medical Hospitalization for Inflammatory Bowel Disease

Background:
It has been reported through national database studies and metanalyses that the relative risk of venous thromboembolism (VTE) is estimated at approximately 2% in all patients with inflammatory bowel disease (IBD) and as high as 8% during the period of active IBD. These larger database analyses lack the granularity to exclude patients with confounding risk factors and include both medical and surgical admissions in patients with a history of IBD. The goal of this study is to evaluate the rate of post-hospitalization VTE specifically in medically treated patients with IBD patients and identification of clinical risk factors.
Methods:
A retrospective cohort was identified from the IBD database of prospectively collected clinical data between 2010 and 2023 through the EPIC electronic medical record at the University of Iowa Hospitals and Clinics. Inclusion criteria included adult patients with a diagnosis of Crohn’s disease or ulcerative colitis within 6 months of hospitalization for an IBD flare. Exclusion criteria included confounding comorbidities associated with hypercoagulability, surgical procedures, and prior VTE. Clinical risk factors were identified after case control matching for disease phenotype and IBD treatment. Clinical variables analyzed included duration of disease, inflammatory biomarkers, albumin levels, hemoglobin, duration of steroid treatment, outpatient IBD medications, smoking history, and Charlson Comorbidity Index. Statistical analysis was completed with Wilcoxon rank sum and Fisher’s exact test with univariate logistic regression for significance.
Results:
2500 subjects were identified with 7 cases of post hospitalization VTE (0.2%) following a medical admission for IBD treatment over a 13-year period. Length of stay and albumin nadir were identified as statistically significant risk factors for the development of VTE. Average time to diagnosis of VTE following discharge was 20 days (CI: 9,25).
Conclusions:
The rate of VTE is low in our cohort of patients following IBD hospitalization specifically identified for medically treated flares without other confounding risk factors for VTE. This low rate is supported by a previously published study analyzing medically treated patient (0.5%). Furthermore, we identified that increased length of hospitalization and low albumin values were risk factors for developing VTE in medically treated patients and may correlate with an increased disease severity state. Given the low incidence of post-hospitalization VTE in our cohort, no recommendation can be made at this time for extended VTE prophylaxis following hospitalization for an IBD flare. However, patients with these risk factors should be monitored closely for about a month after discharge for the development of VTE even without a history of surgery or other thrombotic risk factors.