Tricky Problems with Small Numbers: Methodological Challenges and Possible Solutions for Measuring PCMH and ACO Performance

The underlying changes in cost of care for populations served by patient-centered medical homes (PCMHs) and accountable care organizations (ACOs) are difficult to accurately assess when there are a small number of attributed patients. This issue brief identifies methodological challenges in measuring cost of care performance for organizations with a small number of attributed patients, and provides concrete strategies and resources for state purchasers to address this methodological challenge when evaluating PCMH and ACO cost performance and applying financial incentives and disincentives.

ACO News is a feature of the Medicaid Accountable Care Organization Resource Center, an online collection of tools designed to help Medicaid agencies develop and launch accountable care organizations.