Who explicitly requests the ordering of computed tomography for emergency department patients? A multicenter prospective study.

Emergency department (ED) computed tomography (CT) use has increased substantially in recent years, resulting in increased radiation exposure for patients. Few studies have assessed which parties contribute to CT ordering in the ED. The objective of this study was to determine the proportion of CT scans ordered due to explicit requests by various stakeholders in ED patient care. This is a prospective, observational study performed at three university hospital EDs. CT scans ordered during research assistant hours were eligible for inclusion. Attending emergency physicians (EPs) completed standardized data forms to indicate all parties who had explicitly requested that a specific CT be performed. Forms were completed before the CT results were known in order to minimize bias. Data were obtained from 77 EPs regarding 944 CTs. The parties most frequently requesting CTs were attending EPs (82.0 %, 95 % CI 79.4-84.3), resident physicians (28.6 %, 95 % CI 25.8-31.6), consulting physicians (24.4 %, 95 % CI 21.7-27.2), and admitting physicians (3.9 %, 95 % CI 2.9-5.4). In the 168 instances in which the attending EP did not explicitly request the CT, requests most commonly came from consulting physicians (51.2 %, 95 % CI 43.7-58.6), resident physicians in the ED (39.9 %, 95 % CI 32.8-47.4), and admitting physicians (8.9 %, 95 % CI 5.5-14.2). EPs were the sole party requesting CT in 46.2 % of cases while multiple parties were involved in 39.0 %. Patients, families, and radiologists were uncommon sources of such requests. Emergency physicians requested the majority of CTs, though nearly 20 % were actually not desired by them. Admitting, consulting, and resident physicians in the ED were important contributors to CT utilization.