Emergency department CT of the abdomen and pelvis: preferential utilization in higher complexity patient encounters.

Purpose: The aim of this study was to assess the association of patient encounter complexity and the utilization of CT of the abdomen and pelvis (CTAP) in the emergency department (ED) setting.
Methods: Using 5% research identifiable files for 2007, ED visits for Medicare fee-for-service beneficiaries were identified. Contemporaneous ED physician evaluation and management codes were used as the basis for patient complexity categorization. Encounters in which CTAP was performed on the same date of service were identified, and variables affecting the utilization of CTAP were analyzed.
Results: Of 1,081,000 ED encounters, 306,401 (28.3%) were of lower complexity and 774,599 (71.7%) were of higher complexity. CT of the abdomen and pelvis was performed in 65,273 of all encounters (6.0%), corresponding to 4,069 (1.3%) of lower complexity and 61,204 (7.9%) of higher complexity encounters (odds ratio, 5.95; 95% confidence interval, 5.76-6.14). Of the 65,273 ED encounters associated with CTAP, 61,204 (93.8%) were of higher complexity.
Conclusions: Of patients undergoing CTAP in the ED setting, a very large majority (93.8%) are clinically complex. CT of the abdomen and pelvis is 5.95 times more likely to be utilized in higher than lower complexity ED patient encounters.
(Copyright © 2012 American College of Radiology. Published by Elsevier Inc. All rights reserved.)