A Test of Knowledge About Prostate Cancer Screening

BACKGROUND: Although the benefits of prostate cancer screening are uncertain and guidelines recommend that physicians share the screening decision with their patients, most U.S. men over age 50 are routinely screened, often without counseling. OBJECTIVE: To develop an instrument for assessing physicians' knowledge related to the U.S. Preventive Services Task Force recommendations on prostate cancer screening. PARTICIPANTS: Seventy internists, family physicians, and general practitioners in the Los Angeles area who deliver primary care to adult men. MEASUREMENTS: The authors assessed knowledge related to prostate cancer screening (natural history, test characteristics, treatment effects, and guideline recommendations), beliefs about the net benefits of screening, and prostate cancer screening practices for men in different age groups, using an online survey. They constructed a knowledge scale having 15 multiple-choice items. RESULTS: Participants' mean knowledge score was 7.4 (range 3 to 12) of 15 (Cronbach's a=0.71). Higher knowledge scores were associated with less belief in a mortality benefit from prostate-specific antigen (PSA) testing (r=-.49, P<.001). Participants could be categorized as low, age-selective, and high users of routine PSA screening. High users had lower knowledge scores than age-selective or low users, and they believed much more in mortality benefits from PSA screening. CONCLUSIONS: Based on its internal consistency and its correlations with measures of physicians' net beliefs and self-reported practices, the knowledge scale developed in this study holds promise for measuring the effects of professional education on prostate cancer screening. The scale deserves further evaluation in broader populations.