title: Relation of physicians' predicted probabilities of pneumonia to their utilities for ordering chest x-rays to detect pneumonia.
abstract: To investigate the relation between physicians' predicted probabilities of pneumonia and their utilities for ordering chest x-rays to detect pneumonia, the authors studied 52 physicians who ordered chest x-rays of 886 patients presenting to an emergency department with fever or respiratory complaints. Physicians estimated the probability of pneumonia prior to obtaining the results of the chest x-ray. Utilities were assessed by asking physicians to consider a hypothetical patient presenting with acute respiratory symptoms, with unknown chest x-ray status, and to rank on a scale from +50 ("best thing I could do") to -50 ("worst thing I could do") their rating scale utilities for not diagnosing pneumonia and not ordering a chest x-ray when the patient had pneumonia (i.e., missing a pneumonia), and for diagnosing pneumonia and ordering a chest x-ray when the patient did not have pneumonia (i.e., ordering an unnecessary x-ray). The utility for ordering an unnecessary x-ray was negatively correlated with average predicted probability (r = -0.1495, p = 0.29), whereas the utility for missing a pneumonia was positively correlated with average predicted probability (r = 0.2254, p = 0.11), although the correlations were not statistically significant. Relative chagrin, defined as the difference in these utilities, was significantly inversely correlated with average predicted probability (r = -0.2992, p less than 0.035), even after adjusting for the prevalence of pneumonia seen by each physician (partial r = -0.42, p less than 0.0027). It is concluded that physicians who experienced greater regret over missing a pneumonia than over ordering an unnecessary x-ray estimated lower probabilities of pneumonia for patients for whom they ordered x-rays.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, University of Illinois Medical Center, Chicago 60680.
authors.forename: P S
authors.initials: PS
authors.lastname: Heckerling
authors.forename: T G
authors.initials: TG
authors.lastname: Tape
authors.forename: R S
authors.initials: RS
authors.lastname: Wigton
mesh_terms: D003362:Cost-Benefit Analysis; D003657:Decision Making; D004636:Emergency Service, Hospital; D006785:Hospitals, University; D006801:Humans; D007087:Illinois / Q000453:epidemiology; D008505:Medical Staff, Hospital / Q000523:psychology*; D011014:Pneumonia / Q000000981:diagnostic imaging* / Q000191:economics / Q000453:epidemiology; D010818:Practice Patterns, Physicians' / Q000592:standards*; D011237:Predictive Value of Tests; D013902:Radiography, Thoracic / Q000191:economics / Q000592:standards / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires