Change in clinical practice after publication of guidelines on breast cancer treatment.

Objective: Several studies raise questions about whether clinical practice guidelines actually guide practice. We evaluated patterns of use of breast-conserving surgery (BCS) over time to examine the effect of guideline publication.

Design: Retrospective analysis of time-series data on breast cancer treatment. Multiple logistic regression analysis was performed, adjusting for covariates including the patient's age, comorbidity status and admission year, to assess whether the use of BCS was higher after publication of treatment guidelines.

Setting: Five teaching hospitals participating in the Quality Improvement/Indicator Project (QIP) in Japan.

Participants: Female breast cancer patients who received surgical treatment at five teaching hospitals from January 1996 through December 2007 (n = 2199).

Main Outcome Measure: Rates of use of BCS.

Results: The proportion of BCS use increased from 26.4% before guideline publication to 59.9% after guideline publication in Japan. After controlling for other characteristics, the use of BCS has increased significantly over time, especially since 2001. Women aged 70 years and older (P=0.004) and those with any comorbidity (P < 0.001) were significantly less likely to receive BCS.

Conclusions: This study demonstrated that the adjusted proportion of BCS has increased dramatically since 2001, 2 years after guideline publication in Japan and this is consistent with a relationship between guideline publication and a change in this clinical practice.