—Between 1993 and 1994, the 80 physicians in the French comprehensive cancer center, Léon Bérard, developed and implemented a Clinical Practice Guidelines (CPGs) project based on an analysis of the literature and a consensus of intrainstitutional experts.
—The aims of this project are to assist community-based oncologists in their decision making and to minimize inappropriate variation in practices. A study was designed to assess the impact of CPGs on management of breast and colon cancer.
—A "before-after" study, using institutional computerized records of patients with breast or colon cancer.
—Records for 100 women with localized breast cancer were randomly selected from those available in 1993 and 1995, and those for all patients newly referred with colon cancer in 1993 and 1995 (77 and 81 patients, respectively). Medical decisions on these records were analyzed to assess their compliance with the CPGs. (A systematic search of the literature was performed to determine the scientific evidence for noncompliant decisions.)
—Of 375 available medical decisions, 350 were assessable. The compliance rate with CPGs for breast cancer was significantly higher in 1995 compared with 1993, 54% (54/99; 95% confidence interval [CI], 44%-64%) vs 19% (18/95; 95% CI, 11%-27%) (P<.001). The compliance rate for colon cancer was also significantly higher in 1995 than in 1993, 70% (62/88; 95% CI, 60%-80%) vs 50% (34/68; 95% CI, 38%-62%) (P=.009). In 1993, 42% (40/95; 95% CI, 32%-52%) of medical decisions for breast cancer and in 1995, 68% (67/99; 95% CI, 59%-77%) conformed with the CPGs or were judged to be based on "scientific evidence." In 1993, 71% (48/68; 95% CI, 60%-81%) of medical decisions for colon cancer, and in 1995 81% (71/88; 95% CI, 73%-89%) conformed with the CPGs or were judged to be based on scientific evidence.
—Compliance rates were significantly higher in 1995 for both cancers. The development and implementation of CPGs for cancer management seem to result in significant changes in medical practice, although a causal relationship between changes and CPGs is not demonstrated in this study.