Successful integration of CDs into PACS has the potential to reduce the number of imaging studies performed in hospital emergency departments, according to a two-part study conducted at Brigham and Women’s Hospital in Boston and published in the May issue of Radiology.
Approximately 2.2 million patients are transferred between U.S. hospital emergency departments each year, with diagnostic imaging frequently a key factor in evaluating them, write researcher Aaron Sodickson, MD, PhD, of the department of radiology at Brigham and Women’s Hospital, and his colleagues. The purpose of the study, they note, was to test the hypothesis that CD import into PACS could lead to a decrease in repeat exams. “Physicians often order repeat imaging examinations that are available on CD because of issues related to poor navigation tools or because of inoperable, inaccessible, or lost CDs,” they assert.
The study involved an analysis of the impact of a CD import system on 1,487 patients who had been consecutively transferred to Brigham and Women’s emergency department between February 1, 2009 and August 31, 2009. That data were compared with a previous historical group of 254 patients who had been transferred to the hospital between August 2007 and January 2008, prior to the implementation of the system.
Images for 1,161 of the 1,487 patients in the post-implementation group were successfully imported into PACS. These patients underwent a collective 2,221 exams, 68% of which included CT imaging. In calculating imaging utilization within the first 24 hours after CD import, the researchers determined that the “successful-import” group had a mean rate of 2.74 exams per patient, 17% lower than the mean rate of 3.30 exams per patient in the “failed-import” group. Moreover, the researchers found that successful CD import led to fewer subsequent CT scans, at a respective 1.19 and 1.41 scans per patient in the successful- and “failed-import” groups. Regarding scans obtained in the emergency department, the study specifies, physicians ordered 0.84 scans per “successful-import” patient and 0.99 scans per “failed-import” patient, according to the authors. Compared with the historical control group, for which the mean CT utilization rate was 1.18 CT scans per patient in the emergency department, the “successful-import” group had a 29% decrease in CT utilization.
Sodickson and his colleagues attribute the drop in subsequent imaging largely to decreased repeat imaging, based on the fact that 29% of outside CD studies were repeated in Brigham and Women’s emergency department before the CD import system was implemented. By their calculations, an estimated 35% of the repeat studies could have been avoided. The study showed a repeat rate of 16% for CT images ordered in the emergency department—“a greater than expected reduction in CT utilization,” the researchers say.
The researchers acknowledge that decreases in utilization observed from the historical cohort and the current successful-import group may have been related to an overall interval decrease in imaging utilization. They also concede that the three cohorts were not identical, which might have influenced subsequent imaging orders, and that a single-institution study may not be generalized to all institutions.
“However, if our results are ‘generalizable’ to the approximately 2.2 million emergency department transfer patients per year, our observed reductions in post-transfer CT utilization (from 1.41 to 1.19 CT scans per transfer patient) would be estimated to result in a decrease of 484,000 CT scans per year in the U.S,” the researchers write.
“It is imperative that imaging be used judiciously, and that any unnecessary imaging be eliminated whenever reasonably possible.”
In the study findings, Sodickson and his colleagues also deem CT import into PACS “an imperfect interim solution,” with a failure rate of 22%. Medical records, image repositories, or robust image transfer networks could address the shortcomings associated with the CD import process, they conclude.
