A Clinical Predictive Model for Post-hospitalisation Venous Thromboembolism in Patients With Inflammatory Bowel Disease

Jeffrey D. McCurdy; Amanda Israel; Maryam Hasan; Robin Weng; Ranjeeta Mallick; Tim Ramsay; Marc Carrier


Aliment Pharmacol Ther. 2019;49(12):1493-1501. 

In This Article

Abstract and Introduction


Background: Patients with inflammatory bowel disease (IBD) are at increased risk of venous thromboembolism (VTE) during hospitalisation and potentially post-discharge.

Aims: To determine the incidence and risk factors for post-discharge VTE in IBD patients and create a point of care predictive model to assess VTE risk.

Methods: Hospitalised IBD patients were identified from our institutional discharge database between 2009 and 2016, and were assessed for VTE by chart review. Risk factors for VTE within 3 months of discharge were determined by univariable and multivariable logistic regression. A point of care model was created using variables from the univariate analysis with P < 0.05, and internally validated by bootstrap methods.

Results: Sixty-six of 2161 eligible discharges (3%) were associated with VTE within 6 months of hospitalisation. The median time to event was 37 days (range 3–182 days). On multivariable analysis age >45 years (OR 3.76; 95% CI 1.80–7.89) and multiple admissions (OR 2.62; 95% CI 1.34-5.11) were independently associated with VTE risk. Our final model incorporated age >45 years, multiple admissions, intensive care unit admission, length of admission >7 days and central catheter and was able to discriminate between discharges associated with and without VTE (optimism-corrected c-statistic, 0.70; 95% CI 0.58-0.77). By limiting treatment to a high-risk group, extended thromboprophylaxis could be avoided in 92% of discharges with a miss rate of 1.6% (32/1982 discharges).

Conclusion: Patients with IBD remain at risk of VTE after hospital discharge. Our model may help clinicians stratify which patients will benefit most from extended thrombophrophylaxis.


Venous thromboembolism (VTE) is a common, potentially fatal, yet often preventable medical problem. It is associated with substantial morbidity and is the third leading cause of cardiovascular mortality.[1–4] Although the absolute risk appears greatest during hospitalisation, recent epidemiological studies suggest that the risk may persist up to 90 days beyond hospital discharge in medically ill patients.[5,6]

Inflammatory bowel disease (IBD) is a well-established risk factor for VTE. Intestinal inflammation causes a prothrombotic state, and when coupled with immobility due to severe illness, malnutrition and surgical requirements, patients with IBD are at high risk for VTE.[7] Several meta-analyses of population-based studies found a nearly threefold increased risk of VTE in IBD patients compared with the general population.[8,9] Furthermore, when compared with 17 other chronic illnesses, only cancer and congestive heart failure carried a higher risk of VTE.[8,10] IBD patients with VTE also have a greater risk of mortality compared to the general population with VTE (2.1-fold increased risk), and IBD patients without VTE (2.5-fold increased risk).[11]

Current guidelines from major gastroenterological societies recommend pharmacologic prophylaxis for hospitalised patients with IBD. Although this period has the greatest absolute risk for VTE, a number of lines of evidence suggest that the risk remains high in the early post-discharge setting.[11,12] For example, intestinal inflammation takes weeks to months to resolve, while complications such as abscesses and fistulas may persist longer. Global markers of coagulation also remained elevated up to 12 weeks after discharge.[13] Furthermore, the vast majority of patients do not receive pharmacologic prophylaxis after discharge. Therefore, the post-discharge setting likely remains a vulnerable period for patients with IBD. A recent study using health administrative date found a substantial risk of VTE following discharge in medical and surgical IBD patients; however, patients were only followed for a total of 6 weeks and potential risk factors for VTE were not assessed.[14] Given the paucity of literature in this area, our aims were to assess the incidence and risk factors for VTE in IBD patients in the post-discharge setting and to create a simple point of care risk stratification tool to guide prophylaxis decisions in the post-discharge setting.