The use of imaging studies and its association with surgical delays, costs and complications in patients with acute appendicitis: a population-based study in Ontario, Canada

Appendicitis is commonly assessed with diagnostic imaging prior to intervention. The study objective was to describe practice patterns of diagnostic imaging for appendicitis and the associations with surgical delays, hospital costs, and complications. This was a population-based cohort study of patients with appendicitis between 2009 and 2015. Imaging was categorized into none, ultrasound, computed tomography (CT), or both. The outcomes were: 1) time from triage to surgery, 2) complication rate and 3) hospital costs. Logistic regression and hierarchical linear regression were used to estimate associations between imaging and outcomes. There were 50,369 study patients. Time to surgery was highest in patients requiring both CT and ultrasound (mean difference 5.0 h 95%CI 4.6–5.4) followed by patients requiring CT (2.7 h 95%CI 2.4–3.0) and ultrasound (mean difference 0.7 h, 95%CI 0.5–1.0), compared to no imaging. Hospital costs were highest in those with both ultrasound and CT ($256 95%CI $28–483) and CT alone ($234 95%CI $75–394), compared with no imaging. Complications were associated with the use of CT (OR 1.08 95%CI 1.00–1.17) and both CT and ultrasound (OR 1.21 95%CI 1.09–1.35) compared with no imaging, but not with ultrasound alone (OR 1.01 95%CI 0.93–1.09). This study demonstrated that type of diagnostic imaging is associated with delays to surgery, especially in those requiring CT scan. In addition, complications and hospital costs are increased in this group. Clinicians could consider ultrasound as the first imaging modality to facilitate more timely surgery and reduced costs.