Risk of Venous Thromboembolism in Hospitalized Patients with Inflammatory Bowel Disease

Background: Current guidelines and most experts recommend pharmacologic venous thromboembolism (VTE) prophylaxis for patients hospitalized with an acute inflammatory bowel disease (IBD) exacerbation.  Quality measures of physician performance further expand this mandate to include patients with a diagnosis of IBD who are hospitalized for any reason. We sought to assess the risk of VTE in patients admitted with a diagnosis of IBD. 

Methods: Trained abstractors from 52 Michigan Hospital Medicine Safety Consortium (HMS) hospitals collected patient-level data including VTE risk factors, preventive measures and events to 90 days on a representative sample of hospitalized medical patients who were discharged between December 2011 and June 2015.  Patients  <18 years old, admitted for VTE, surgery or comfort care, directly admitted to the intensive care unit, or  on anticoagulation treatment were excluded.  We limited our analysis to patients with a history of IBD and further identified those admitted with an acute exacerbation.  We used the Padua Prediction Score to stratify their risk of VTE.  We also identified the type of VTE prophylaxis received and VTE events within 90 days of discharge.  Fisher’s exact test was used to compare VTE event rates.

Results: Of 78,794 patients, 2,365 (3%) had a diagnosis of IBD, 871 (1.1%) of which were classified as an acute exacerbation.  There were 11 (0.5%, 95% CI: 0.2% to 0.8%) VTE events among all patients with IBD, and 4 (0.5%, 95% CI: 0.1% to 1.2%) VTE events among those with an IBD exacerbation on admission.  Using the Padua risk tool, 2,100 (88.8%) of the patients with IBD and 837 (96.1%) of those with an acute IBD exacerbation were considered at low risk for VTE.  Among all patients with IBD, the rate of VTE was 0.3% for those at low risk and 1.5% for those at high risk based on Padua (p = 0.03).  The distribution of VTE events by Padua risk score and type of prophylaxis received is shown in Table 1 for all IBD patients and in Table 2 for those admitted with an acute exacerbation.

Conclusions: The rate of VTE events is low among hospitalized patients with IBD, including those admitted with an acute exacerbation.  Most of these patients are considered at low risk for VTE based on the Padua prediction tool and probably do not require prophylaxis.  Quality measures requiring use of pharmacologic prophylaxis for patients with IBD should be reconsidered.

Table 1.  VTE Events in Hospitalized Patients with Inflammatory Bowel Disease

Table 2.  VTE Events in Hospitalized Patients Admitted with Acute Inflammatory Bowel Disease Exacerbation