Multicenter Randomized Trial of Quantitative Pretest Probability to Reduce Unnecessary Medical Radiation Exposure in Emergency Department Patients With Chest Pain and Dyspnea

Study Questions:

What is the impact of a web-based computer program that provides quantitative pretest probability for patients with symptoms suggesting both acute coronary syndrome (ACS) and pulmonary embolism (PE)?


This was a prospective, four-center, randomized controlled trial of decision support effectiveness. Adult subjects presenting to the emergency department (ED) with chest pain or dyspnea, nondiagnostic electrocardiograms, and no obvious diagnosis were randomized to a control group or intervention group, in which the clinician received pretest probabilities for both ACS and PE, and prescriptive advice. Clinicians in the intervention group answered yes, no, or maybe in response to the question of whether they planned to use the results of the webtool; research assistants made no recommendation. The primary outcome was defined as exposure to >5 mSv estimated effective radiation to the chest and who went on to have no significant cardiopulmonary diagnosis on 90-day follow-up.


Complete data were obtained on 541 patients. One hundred sixty-four (30%) patients had pretest probability estimates <2.5% for both ACS and PE. Those randomized to the intervention group had lower radiation exposure to the chest, lower in-hospital length of stay, and lower charges and estimated costs for medical care within 90 days of the ED visit. In particular, the proportion of patients with >5 mSv to the chest and no cardiopulmonary diagnosis at 90-day follow-up was reduced from 33% in the control group to 25% in the intervention group (p = 0.038). There was no significant difference in the rate of return for care to an ED or the occurrence of adverse events. There was a high degree of discordance in pretest probability between the clinicians and webtool; clinicians had consistently higher pretest probability estimates.


Patients randomized to a web-based computer program that provided pretest probability and recommended clinical actions reduced radiation exposure and cost of care, without an increase in adverse events over 90 days, in patients presenting with symptoms suggestive of ACS and PE.


The authors presented the results of a web-based computer program in which clinicians were presented with pretest probabilities and advice on risk-specific management of patients presenting with ACS and PE. Although the methods in this trial did not allow for clinician adherence to recommended guidelines, those patients randomized to the intervention had lower radiation exposure, lower in-hospital length of stay, and lower cost of care. Such findings have implications for the utility of decision support interventions that characterize pretest probability and provide meaningful prescriptive advice for more than one diagnosis. Future studies should help clarify the role of point-of-care computer-based decision support interventions and inform how such important tools can be incorporated into practice.

Clinical Topics: Acute Coronary Syndromes, Heart Failure and Cardiomyopathies, Vascular Medicine

Keywords: Fees and Charges, Acute Coronary Syndrome, Follow-Up Studies, Chest Pain, Physical Therapists, Pulmonary Embolism, Costs and Cost Analysis, Electrocardiography, Dyspnea, Pregnancy

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