Physicians may not be accurate in their confidence levels of their diagnoses, sa

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Physicians may not be accurate in their confidence levels of their

diagnoses, says Pitt study

30 Mar 2005 Medical News Today

Physicians' often do not have correct perceptions of the accuracy of

their diagnoses at the time they make them, and in significant

numbers of cases they may be overconfident--wrong when they believe

they are right; or underconfident--right when they believe they are

wrong--about their diagnostic assessments, according to a University

of Pittsburgh study.

" An overconfident physician will not seek help or may ignore help

that is offered; someone underconfident may, in extreme cases, be

talked out of what was an accurate assessment, " said P.

Friedman, Ph.D., professor of medicine at the University of

Pittsburgh School of Medicine, in an article published in the April

issue of the Journal of General Internal Medicine. Dr. Friedman

reported that confidence plays a major role in clinicians' use of

outside resources in determining diagnoses and making other medical

decisions. These resources include colleagues, medical books,

journals and computer-based decision support systems (DSSs).

" Decision support occurs in two modes: either clinicians must seek

medical information to supplement what they already know, or if it

is 'pushed' to them in the form of a computer-generated alert or

reminder, they must be open to the advice, " Dr. Friedman said.

" The whole decision support process presupposes that clinicians know

when to seek help or pay attention to help that is offered, " he said,

noting that this study is not about how often physicians are correct,

but rather, when they are correct, whether they are aware of it.

" Dr. Friedman, who is on leave from Pitt to work as a senior scholar

and program officer in the National Library of Medicine at the

National Institutes of Health in Bethesda, Md., and his colleagues

developed detailed written synopses from 36 detailed diagnostically

challenging cases from patient records at the University of Illinois

at Chicago, the University of Michigan and the University of North

Carolina. They recruited 216 volunteer subjects from those three

institutions: 72 fourth-year medical students, 72 second- and third-

year internal medicine residents and 72 general internists with

faculty appointments and at least two years of post-residency

experience.

Each subject worked on nine cases. For each case, subjects were asked

to provide a diagnosis and a measure of their confidence in the

diagnosis.

" Focusing on the residents and faculty physicians, what we found was

that correctness and confidence were not aligned in about 1/3 of the

cases, " Dr. Friedman said. " For those cases where confidence and

correctness were not aligned, physicians were more likely to lack

confidence in a correct diagnosis than the reverse. "

Nonetheless, he added, residents and more experienced internists

were " overconfident, " believing they are correct when in fact they

were not, in 12 to 15 percent of the cases overall.

" Overconfidence is the zone of greatest concern when one thinks about

how to improve practice using information technology, " Dr. Friedman

said. " While this was a study performed in the laboratory and not in

the clinic, the apparent prevalence of overconfidence represents a

major challenge to designers of decision support systems--if the

advice of these systems is to be sought and attended to when it is

really needed. "

Also participating in the study were Guido G. Gatti, M.S., center for

Biomedical Informatics, University of Pittsburgh; M. Franz,

Ph.D., department of psychology, St. Fisher College; Gwendolyn

C. , Ph.D., Division of Community Health, Duke University;

Fredric M. Wolf, Ph.D., department of medical education and

informatics, University of Washington; S. Heckerling, M.D.,

department of medicine, University of Illinois at Chicago; L.

Fine, M.D., department of medicine, University of Michigan; M.

, M.D., department of medicine, University of North Carolina;

and Arthur S. Elstein, Ph.D., department of medical education,

University of Illinois at Chicago.