Prostate cancer is a common and expensive disease with annual spending topping $12 billion. During the past decade, prostate cancer spending has increased by 11% annually, outpacing growth rates for other common conditions such as cardiovascular and pulmonary diseases. This growth is due, in part, to financial incentives afforded by urologist self-referral of diagnostic and therapeutic services. The recent proliferatio of large urology groups has the potential to further amplify these trends. The formation of these large groups has been propagated by their unique investment opportunities, such as ownership interests in expensive equipment to provide intensity modulated radiation therapy and cross-sectional imaging. However, proponents argue that their one-stop model results in better care integration for men with prostate cancer, ultimately yielding better quality at a lower cost. Thus, the goal of this national study is to better understand relationships between urologist practice organization and the quantity, quality and cost of prostate cancer care. To examine this issue more carefully, this grant has the following three aims. Aim 1. To assess relationships between urologist practice organization and prostate cancer utilization. Using national Medicare and SEER-Medicare data, we will measure how prostate cancer detection and treatment are mediated by urologist group practice structure. Aim 2. To measure relationships between urologist practice organization and the quality of prostate cancer care. Using similar methods, we will determine the effect of urologist practice structure on the quality of prostate cancer care including adherence to nationally endorsed standards and the breadth of overuse. Aim 3. To assess relationships between urologist practice organization and prostate cancer expenditures. We will measure the association between urologist practice structure and national Medicare payments, both per capita (i.e., average overall spending) and per episode surrounding local treatment. This proposal has real-world implications for all prostate cancer stakeholders. First, our findings with respect to quality have immediate implications for patients, who are logically interested in mechanisms for improving the quality of prostate care delivered. Second, understanding the relative efficiency of prostate cancer care is of immediate interest to payers and policymakers as they explore strategies to improve quality while limiting unnecessary spending growth.