Login to Access Video or Poster Abstract: MP32-04
Sources of Funding: American Cancer Society (MSRG-15-103-01-CHPHS to MJR), AUA/Urology Care Foundation Rising Stars in Urology Research Program

Introduction

While Accountable Care Organizations (ACOs) continue to proliferate, there remain few empiric data that specifically investigate the effect of ACO enrollment on the cancer diagnosis, treatment, and survivorship. To this end, we characterize the relationship between Medicare Shared Savings Program (MSSP) enrollment and appropriateness of prostate cancer screening.

Methods

We built a cohort of aged Medicare beneficiaries from 2010 through 2013 comprising 17,779,120 person-years and 9,201,163 person-years before and after ACO enrollment, respectively. We characterized our exposure of interest, ACO enrollment, by identifying all MSSP-enrolled primary care providers and recapitulating published attribution strategies, and identified our outcome, PSA screening, through relevant Medicare claims. Using claims from 2006, we fit a model for 5-year overall survival and isolated the highest and lowest quintiles of predicted survival. We then performed differences-in-differences analysis specifically evaluating the interaction between ACO enrollment and the period following ACO intervention (ACO X Post) within the highest and lowest quintiles of predicted survival to characterize between-group differences in change in prostate cancer screening attributable to ACO enrollment across the spectrum of health.

Results

Medicare beneficiaries in the highest and lowest quintiles of predicted survival attributed to MSSP ACO-enrolled PCPs were 4.3% and 1.8% more likely to undergo PSA screening than those attributed to non-ACO primary care providers prior to deployment of the MSSP (p<0.0001 for both). MSSP enrollment was associated with excess reduction in the rate of prostate cancer screening among both appropriate candidates (highest quintile of survival) and inappropriate candidates (lowest quintile of predicted survival), with observed difference-in-difference of 0.86% and 0.67%, respectively (Figure).

Conclusions

ACO enrollment increases the magnitude of observed reductions in prostate cancer screening among both appropriate and inappropriate candidates for early detection. Developing and deploying incentives to target screening to appropriate candidates and withholding screening from those unlikely to benefit will be necessary to optimize early cancer detection in the era of payment innovation.

Funding

American Cancer Society (MSRG-15-103-01-CHPHS to MJR), AUA/Urology Care Foundation Rising Stars in Urology Research Program