Despite concerns about exposing patients to excessive amounts of radiation from CT scans, a Massachusetts General Hospital study finds that such tests avoided hospitalization in nearly one in four patients who came to the ED complaining of abdominal pain.
The research focused on non-traumatic abdominal complaints because they are common reason patients seek emergency department care, yet they are often difficult for a clinician to diagnose. Nevertheless abdominal complaints are a primary reason patients come to an ED, and were said to be responsible for 115 million patient visits in 2005.
The report, published in the American Journal of Roentgenology, compared emergency department clinicians' diagnostic decisions about these patients measured by their responses to a questionnaire at two time points: before an abdominal CT was administered and after the scans were completed.
"CT altered the leading diagnosis in 49% of the patients (284 of 584)...and increased mean physician diagnostic certainty from 70.5% (pre-CT) to 92.2% (post-CT)," the authors found.
Additionally, the "physicians planned to admit 75.3% of the patients (440/584) to the hospital before the CT; that plan was changed to hospital discharge with follow-up in 24.1% of patients (106/440) after CT."
The study was conducted by Hani H. Abdujudeh and colleagues at the Massachusetts General Hospital Department of Radiology from Nov. 2006 through Feb. 2008.
The authors said that prior to the CT, the clinicians surveyed believed 79 of these patients would proceed to surgery. After the scan, 20 of those patients were found to not need surgery and were discharged.
Prior to the CT, clinicians diagnosed with certainty 52 patients with appendicitis, but after the CT only 29 turned out to have that condition. Likewise for diverticulitis. Prior to the CT, that was the clinicians' opinion for 51 patients, but after the CT, only 25 had that diagnosis. While 80 patients were considered to have an intestinal obstruction, the CT determined only 43 needed that procedure.
In some cases, the CT directed physicians to a more serious diagnosis than they would otherwise have given their patients. For example, before a CT scan, five patients would have been diagnosed with pelvic inflammatory disease. After the scan, 19 patients received treatment for PID. Before the CT, eight patients were believed to have cholecystitis or cholangitis. After CT, 16 patients were so diagnosed.
In all, CT changed the course of care for 20 conditions.
The number of patients who were discharged from the hospital rather than were admitted or put into observation status increased by 55% (from 142 to 220 patients).
The authors acknowledge that their study has several limitations. It did not have a control group, and patients were not consecutively enrolled in the study because investigation coordinators were not working around the clock.
However, they conclude that CT scans change the leading diagnosis, increase diagnostic certainty and alter potential patient management decisions.