The Impact of Using Mid-level Providers in Face-to-Face Primary Care on Health Care Utilization

Abstract BACKGROUND: There has been concern that greater use of nurse practitioners (NP) and physician assistants (PA) in face-to-face primary care may increase utilization and spending. OBJECTIVE: To evaluate a natural experiment within Kaiser Permanente in Georgia in the use of NP/PA in primary care. STUDY DESIGN: From 2006 through early 2008 (the preperiod), each NP or PA was paired with a physician to manage a patient panel. In early 2008, NPs and PAs were removed from all face-to-face primary care. Using the 2006-2010 data, we applied a difference-in-differences analytic approach at the clinic level due to patient triage between a NP/PA and a physician. Clinics were classified into 3 different groups based on the percentage of visits by NP/PA during the preperiod: high (over 20% in-person primary care visits attended by NP/PAs), medium (5%-20%), and low (