Implementation of cancer prevention guidelines in clinical practice. Data from several sources, including consumer surveys, physician surveys, and medical record audits, indicate that consumers do not receive cancer screening tests as recommended by the National Cancer Institute, the American Cancer Society, and the U.S. Preventive Services Task Force. Performance rates are consistently below published standards for all tests except Pap tests. Major reasons physicians do not perform the recommended tests include physician forgetfulness, disagreement with recommendations, lack of time, and patient refusal. Physicians also tend to overestimate their own performance rates. Barriers to screening test performance can be categorized into patient factors, physician factors, test factors, and health care delivery system factors. Interventions, such as computerized reminder systems, physician audits with feedback, and patient education and reminders, can be effective in promoting performance of such screening. Interventions that target both physician and patient may be particularly effective. 