CT Imaging Use and Bundling in Simulated Minor Head and Neck Trauma Across Training Levels: A Mixed-Methods Study

Despite the availability of well-validated clinical decision rules, computed tomography (CT) remains overused for low-risk emergency department (ED) patients. In this study, we evaluated CT imaging decision-making patterns across training levels in minor head and neck trauma, a common ED presentation, and identified system-level barriers and facilitators to decision rule use.

We conducted a mixed-methods study at a tertiary care academic ED, administering an electronic survey to 77 participants (28 emergency medicine (EM) attending physicians, 25 EM residents, 24 medical students) and conducting 46 semi-structured interviews following survey completion. Surveys and interviews assessed attitudes toward decision rules and included 10 vignette-based minor head and neck trauma scenarios evaluating CT decision patterns with imaging appropriateness determined using the Canadian CT Head and C-Spine Rules.

Attendings and residents demonstrated higher rates of imaging bundling—defined as ordering both CT head and cervical spine imaging when only one imaging study was indicated—compared with medical students (46% and 69% vs. 21%, p < 0.01), with residents bundling at the highest rate. Attendings reported greater confidence in imaging decisions (mean 4.6/5) than residents (4.2/5) and medical students (3.5/5) (p < 0.01), and residents reported greater confidence than medical students (p < 0.01), while imaging appropriateness scores did not differ across groups. During interviews, attendings and residents described imaging bundling as a practical strategy to streamline care by completing imaging in a single trip, though many voiced uncertainty about whether this practice improves operational flow or benefits patients. Qualitative analysis identified themes of inconsistent decision rule use and training, facilitation by electronic health record (EHR) tools and departmental endorsement of specific rules, and improved communication with patients and consultants when rules were used.

CT overuse and imaging bundling were more common among attendings and residents, suggesting that confidence and experience alone do not translate to better decision rule adherence. Standardizing decision rule use, department endorsement of rule use, and embedding support within the EHR may represent scalable quality improvement opportunities to reduce unnecessary imaging.