Presentation Authors: Parth K. Modi*, Samuel R. Kaufman, Lindsey A. Herrel, James M. Dupree, Brent K. Hollenbeck, Vahakn B. Shahinian, Ann Arbor, MI
Introduction: Active surveillance is the preferred option for men with low risk prostate cancer but the US lags behind other nations in its adoption. We examined the influence of urologist practice organization and intensity-modulated radiation therapy (IMRT) ownership on the use and rate of adoption of observation for men with incident prostate cancer.
Methods: Using national Medicare claims, we identified men with newly diagnosed prostate cancer from 2010 through 2014 and followed through 2015. We identified men not treated within 1 year of diagnosis as having undergone observation. We assigned each patient&[prime]s urologist to a group practice and identified that group&[prime]s organization (e.g. multispecialty group, single specialty group, solo practice) using data from the Medicare Data on Provider Practice and Specialty file. We also determined each practice&[prime]s IMRT ownership using a claims algorithm. We fit mixed effects logistic regression models to identify predictors of observation and the rate of observation use over time, adjusting for patient factors.
Results: Of 22,178 men with incident prostate cancer treated by 350 practices, 4,418 (19.9%) underwent observation. Multispecialty groups had the highest use of observation (22.7%, 95% confidence interval [95%CI] 21.0-24.3%), while single specialty (large 19.6% [95%CI 18.3-20.9%] P=0.003, small 20.3% [95%CI 19.0-21.6%] P=0.02) and specialist-only groups (11.7% [95%CI 8.6-14.9%] P < 0.001) were less likely to observe patients. Small single specialty and specialist groups increased their use of observation more than multispecialty groups (Figure). Across group types, 7,832 (35.3%) men were managed in practices that had an ownership interest in IMRT. Groups owning IMRT were less likely to use observation than non-owners (17.4% [95%CI 16.1-18.6%] v 21.4% [95%CI 20.5-22.4%], P < 0.001). However, there was no difference in the rate of adoption between IMRT owning and non-owning groups.
Conclusions: While observation is increasingly used for men with incident prostate cancer, the rate of increase varies by urologist group practice type, but independently of IMRT ownership. As physician groups consolidate, the resulting group practice landscape is important for understanding the continued adoption of active surveillance for prostate cancer.
Source of Funding: This work was supported by NCI F32CA232332 (PKM) and AHRQ R01HS257007 (BKH, VBS)