LAUSR

Background: Vertical and horizontal integration among health care providers has transformed the practice arrangements under which many physicians work. Objective: To examine the influence of type of practice structure, and by implication the financial incentives associated with each structure, on treatment received among men newly diagnosed with low-risk prostate cancer. Research Design: We compiled a unique database from cancer registry records from 4 large states, Medicare enrollment and claims for the years 2005−2014 and SK & A physician surveys corroborated by extensive internet searches. We estimated a multinomial logit model to examine the influence of urologist practice structure on type of initial treatment received. Results: The probability of being monitored with active surveillance was 7.4% and 4.2% points higher for men treated by health system and nonhealth system employed urologists (P<0.01), respectively, in comparison to men treated by single specialty urology practices. Among multispecialty practices, the rate of active surveillance use was 3% points higher compared with single specialty urology practices(P<0.01). Use of intensity modulated radiation therapy among urologists with ownership in intensity modulated radiation therapy was 17.4% points higher compared with urologists working in small single specialty practices. Conclusions: Physician practice structure attributes are significantly associated with type of treatment received but few studies control for such factors. Our findings—coupled with the observation that urologist practice structure shifted substantially over this time period due to mergers of small urology groups—provide one explanation for the limited uptake of active surveillance among men with low-risk disease in the US.