The effects of physicians' training and personality on test ordering for ambulatory patients.

We studied records of 351 hypertensive patients cared for by 30 internists in private office practice. We correlated the use of outpatient diagnostic tests with personal characteristics of the prescribing physicians. Doctors trained in medical schools with academic orientations used more tests than other physicians. Patterns of use were not strongly related to the number of years since medical school graduation, or physicians "intolerance of ambiguity" as measured by a standard psychological instrument. These findings suggest that certain types of training may predispose physicians to be high testers.