Persistently High Rates of Abdominal Computed Tomography Imaging Among Patients With Inflammatory Bowel Disease Who Present to the Emergency Department.

Background: Recent guidelines recommended judicious use of abdominal computed tomography (CT) in the emergency department (ED) for inflammatory bowel disease. Trends in CT utilization over the last decade, including since the implementation of these guidelines, remain unknown.

Methods: We performed a single-centre, retrospective study between 2009 and 2018 to assess trends in CT utilization within 72 h of an ED encounter. Changes in the annual rates of CT imaging among adults with IBD were estimated by Poisson regression and CT findings by Cochran-Armitage or Cochran-Mantel Haenszel tests.

Results: A total of 3000 abdominal CT studies were performed among 14,783 ED encounters. CT utilization increased annually by 2.7% in Crohn's disease (CD) (95% confidence interval [CI], 1.2 to 4.3; P = 0.0004), 4.2% in ulcerative colitis (UC) (95% CI, 1.7 to 6.7; P = 0.0009) and 6.3% in IBD unclassifiable (95% CI, 2.5 to 10.0; P = 0.0011). Among encounters with gastrointestinal symptoms, 60% with CD and 33% with UC underwent CT imaging in the final year of the study. Urgent CT findings (obstruction, phlegmon, abscess or perforation) and urgent penetrating findings alone (phlegmon, abscess or perforation) comprised 34% and 11% of CD findings, and 25% and 6% of UC findings, respectively. The CT findings remained stable overtime for both CD (P = 0.13) and UC (P = 0.17).

Conclusion: Our study demonstrated persistently high rates of CT utilization among patients with IBD who presented to the ED over the last decade. Approximately one third of scans demonstrated urgent findings, with a minority demonstrating urgent penetrating findings. Future studies should aim to identify patients in whom CT imaging is most appropriate.