State-Level Evaluation of Washington's State Innovation Models (SIM) Initiative

The Washington State Innovation Models (SIM) $65 million Test Award from the Center for Medicare & Medicaid Services' Innovation Center is a statewide intervention expected to improve population health, quality of care, and cost growth through four initiatives: 1) regional accountable communities of health linking health and social services to address local needs; 2) a practice transformation support hub; 3) four value-based payment reform pilot projects mainly in state employee and Medicaid populations; and 4) data and analytic infrastructure development to support system transformation with common measures. We develop a conceptual model based on diffusion theory and apply the RE-AIM evaluation framework (Reach, Effectiveness, Adoption, Implementation, and Maintenance) to structure our evaluation. We find that in three years (2016–2018), SIM built the infrastructure for system transformation and increased Washington's readiness for health system change in the next decade. However, the initiatives have not spread statewide, which may take over 10 years.