Abstract
PURPOSE: We describe the longitudinal adoption of conservative management (ie, the absence of treatment) for prostate cancer among urology group practices in the United States and identify group practice features that influence this adoption. METHODS: Using a 20% sample of Medicare claims, we identified men with incident prostate cancer from 2010 through 2014 and assigned each to his predominant urologist. We linked each urologist to a practice and characterized the practice's organization (eg, solo, single specialty, multispecialty) and ownership of intensity-modulated radiation therapy. For each group, we determined the rate of conservative management within 1 year of diagnosis. We then fit mixed-effects logistic regression models to assess relationships between practice organization and the adoption of conservative management over time, adjusted for patient characteristics. RESULTS: We identified 22,178 men with newly diagnosed prostate cancer managed by 350 practices. Practices that increased use the most over time also used conservative management the most in 2010, whereas those that increased use the least used conservative management the least in 2010. Thus, the difference in average use of conservative management between highest- and lowest-use practices widened between 2010 and 2014. Urology groups increased their use of conservative management more rapidly than multispecialty groups. There was no difference in the rate of increase between intensity-modulated radiation therapy owning and nonowning groups. CONCLUSION: There is increasing variation among group practices in the use of conservative management for prostate cancer. This underscores the need for a better understanding of practice-level factors that influence prostate cancer management.