Patients' anxiety and expectations: how they influence family physicians' decisions to order cancer screening tests.

OBJECTIVE To compare the influence of physicians' recommendations and patients' anxiety or expectations on the decision to order four cancer screening tests in clinical situations where guidelines were equivocal: screening for prostate cancer with prostate-specific antigen for men older than 50; breast cancer screening with mammography for women 40 to 49; colorectal cancer screening with fecal occult blood testing; and colorectal cancer screening with colonoscopy for patients older than 40.

DESIGN Cross-sectional mailed survey with clinical vignettes.

SETTING British Columbia, Alberta, Ontario, Quebec, and Prince Edward Island.

PARTICIPANTS Of 600 randomly selected family physicians in active practice approached, 351 responded, but 35 respondents were ineligible (response rate 62%).

MAIN OUTCOME MEASURES Decisions to order cancer screening tests, physicians' perceptions of recommendations, patients' anxiety about cancer, and patients' expectation to be tested.

RESULTS For all screening situations, physicians most likely to order the tests believed that routine screening with the test was recommended; physicians least likely to order tests believed routine screening was not. Patients' expectations or anxiety, however, markedly increased screening by physicians who did not believe that routine screening was recommended. In regression models, the interaction between physicians' recommendations and patients' anxiety or expectation was significant for all four screening tests. When patients had no anxiety or expectations, physicians' beliefs about screening strongly predicted test ordering. Physicians who believed routine screening was recommended ordered the test in most cases regardless of patient characteristics. But patients' anxiety or expectations markedly increased the probability that the test would be ordered. The probability of test ordering went from 0.28 to 0.54 for prostate-specific antigen (odds ratio [OR] = 1.9), from 0.15 to 0.44 for mammography (OR = 2.8), from 0.33 to 0.79 for fecal occult blood testing (OR = 2.4), and from 0.29 to 0.65 for colonoscopy (OR = 2.2).

CONCLUSION Differences in clinical judgment about recommended practice lead to practice variation, but physicians are also influenced by nonmedical factors, such as patients' anxiety and expectations of receiving tests. In terms of magnitude of influence, clinical judgment is more powerful than nonmedical patient factors, but patient factors are also powerful drivers of family physicians' decisions about cancer screening when practice guidelines are equivocal.