For this study, the authors used the national Medicare claims data, identifying men with newly diagnosed prostate cancer from 2010 to 2014 and followed through 2015. Men not treated within 1 year of diagnosis were identified as having undergone observation. The authors assigned each patient’s urologist to a group practice and identified that group’s organization (e.g. multispecialty group, single specialty group, solo practice) using data from the Medicare Data on Provider Practice and Specialty file. They also determined each practice’s IMRT ownership using a claims algorithm. Mixed effects logistic regression models were used to identify predictors of observation and the rate of observation use over time, adjusting for patient factors.
There were 22,178 men with incident prostate cancer treated by 350 practices. Among these patients, 4,418 (19.9%) underwent observation. Multispecialty groups had the highest use of observation (22.7%, 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:
Across all group types, 7,832 (35.3%) men were managed in practices that had an ownership interest in IMRT. These groups 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). Interestingly, there was no difference in the rate of adoption between IMRT owning and non-owning groups.
These results assessing the relationship between IMRT owners and non-owners, practice type, etc and the impact on observation/active surveillance rates are crucial and may help explain why the US lags behind other developed nations with regards to uptake of active surveillance in appropriately selected individuals. Dr. Modi conclude that 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.
Presented by: Parth Modi, MD, MS, University of Michigan, Ann Arbor, MI
Co-Authors: Samuel R. Kaufman, Lindsey A. Herrel, James M. Dupree, Brent K. Hollenbeck, Vahakn B. Shahinian, Ann Arbor, MI
Written By: Zachary Klaassen, MD, MSc – Assistant Professor of Urology, Georgia Cancer Center, Augusta University - Medical College of Georgia @zklaassen_md at the American Urological Association's 2019 Annual Meeting (AUA 2019), May 3 – 6, 2019 in Chicago, Illinois