Inappropriate requests for cranial CT scans in emergency departments increase overuse and reduce test performance

Purpose: The number of non-traumatic urgent cranial computed tomography (NT-UCCT) is exponentially increasing but limited research has been conducted on the quality of clinical justification. Accordingly, we aimed (1) to assess how clinical information in the electronic NT-UCCT request agreed with that provided in the patient's emergency department discharge summary and (2) to analyze the potential effect of those discrepancies on the NT-UCCT overload.

Material and methods: Patients undergoing NT-UCCT in 2017-2021 were randomly selected for this retrospective research-board-approved study. Signs and symptoms (S/S) in electronic request and emergency department discharge summary, acute and relevant computed tomography (CT) findings (acute ischemia or hemorrhage, masses, brain edema, or previously undetected hydrocephalus), and final diagnosis at emergency department discharge summary were collected. Concordance between digital request and emergency department discharge summary and their association with both acute and relevant CT findings and final diagnosis were analyzed.

Results: We recruited 156 patients: 80 men; mean age, 55. Acute, relevant CT findings were detected in 28 cases (17.9%). The final diagnosis was neurological disease, non-neurological disease, and no definitive diagnosis in 46 (29.5%), 58 (37.2%), and 51 (32.7%) cases, respectively. Full agreement between the electronic request and emergency department discharge summary occurred in only 36 patients (23.1%). Motor deficit was the most frequent false positive electronic request S/S (18; 11.54%), having low positive predictive value (30.30%; 95%CI 15.59-48.71%) and worst association with acute relevant CT findings than when true positive (OR 2.54; 95%CI 0.04-6.21 vs. OR 6.26, 95%CI 2.21-17.78). Nausea/vomiting was the third most common false negative electronic request S/S (13; 10.26%) and reduced the likelihood of acute and relevant CT findings (OR 0.126; 95%CI 0.016-0.971; p = 0.020). False S/S in electronic request predominated in non-neurological diseases (50-60.2% vs. 33-39.8%; p = 0.068).

Conclusion: Discrepancies between electronic request and emergency department discharge summary were observed in >75% of patients, leading to unnecessary NT-UCCT tests.