Practice Model Trends in Medicare Payments Across States and Regions.

Anesthesia delivery models have long been shaped by workforce trends, state and federal regulations, economic incentives driven by reimbursement, and the normative preferences of provider and facility organizations. In recent years, there has been a significant shift toward greater use of more efficient certified registered nurse anesthetist (CRNA)-oriented delivery models observed at the national level Medicare data. However, given the wide range of these factors across states and regions, this shift has likely occurred at an uneven pace. This study analyzes the influence of provider workforce composition and CRNA scope of practice (SOP) regulations on usage of competing types of anesthesia delivery models, including anesthesiologist alone, care team, and undirected CRNA models. Results show that over the period from 2010-2019, anesthesia delivery models utilized under Medicare Part B have become increasingly oriented around the use of CRNAs. However, increases in the care team vs undirected CRNA model are highly uneven and inconsistent across states, even after adjusting for workforce and SOP. Speculation on additional normative or organization-driven reasons for persistent use of inefficient delivery models in some places is offered.