Outside Imaging in Emergency Department Transfer Patients: CD Import Reduces Rates of Subsequent Imaging Utilization

PURPOSE: To test the hypothesis that among emergency department (ED) transfer patients, CD import of outside examinations into the picture archiving and communication system (PACS) decreases imaging utilization in the subsequent 24 hours. MATERIALS AND METHODS: Institutional review board approval was obtained for this HIPAA-compliant study, with waiver of informed consent for retrospective medical records review. In 1487 consecutive ED patients, CD import to PACS was attempted between February 1 and August 31, 2009. Subsequent rates of imaging performed within 24 hours of any CD import attempt were extracted from the electronic medical record and compared between two patient groups: those with successful CD import and those for whom CD import had failed. Rates of all subsequent imaging and of computed tomographic (CT) imaging alone were compared by using the Wilcoxon rank sum test. ED CT utilization in the successful-import group was compared with that in a historical control group of 254 consecutive ED patients transferred with outside hospital CDs between August 2007 and January 2008, prior to implementation of import procedures. RESULTS: CD import to PACS was successful in 78% (1161 of 1487) of patients. Successful CD import produced a 17% reduction (P < .001) in mean rates of all subsequent diagnostic imaging, from 3.30 to 2.74 examinations per patient in the failed-import and successful-import groups, respectively, and a 16% reduction (P = .01) in subsequent CT utilization from mean of 1.41 to 1.19 scans per patient in those respective groups. Compared with the historical control group, posttransfer utilization of CT in the ED was reduced by 29% (P < .001) from 1.18 (historical control group) to 0.84 (successful-import group) scans per patient. CONCLUSION: Among ED transfer patients, CD import of outside imaging from the sending institution into the receiving institution's PACS significantly decreased the rates of subsequent imaging utilization.