Factors influencing use of the prostate-specific antigen screening test in primary care

To evaluate the use of the prostate-specific antigen (PSA) test and digital rectal examination (DRE) in prostate cancer screening by primary care physicians.

Physician survey and retrospective medical record review.

We randomly selected and reviewed the medical records of 3 cross-sectional samples of male patients and surveyed their primary care physicians at 1-year intervals. All the physicians practiced in Colorado. The study spanned 3 years, including late 1992, when the American Cancer Society recommended the use of PSA in a prostate cancer screening guideline.

We reviewed the medical records of 4772 male patients and surveyed 109 primary care physicians. We found that PSA testing for men aged 50 or older increased significantly from 1992 to 1994, from 24% in 1992 to 35% in 1993 and 40% in 1994 (overall odds ratio, 2.94; P < .05). Over the same time period, the DRE rate remained relatively unchanged (39% in 1992, 41% in 1993, and 36% in 1994). Overall PSA use was positively associated with patient age greater than 59 years, patient non-smoking status, physician "readiness to change cancer screening behavior," private insurance status, and nonsolo practice. Before the release of a prostate cancer screening guideline, participating physicians cited the American Cancer Society as the organization that most influenced their practice with respect to cancer screening. The magnitude of the reported influence of the American Cancer Society was correlated with the subsequent use of PSA in 1994 by primary care physicians after adjustment for change in DRE and baseline PSA rates, although the association did not reach statistical significance in multivariable regression models.

Primary care physicians in Colorado significantly increased their use of the PSA test from 1992 to 1994, during which time the American Cancer Society issued a guideline recommending the use of PSA for prostate cancer screening. The reported influence of the American Cancer Society on cancer screening practices correlated with the subsequent increase in PSA testing.