Does expanded state scope of practice for nurse practitioners and physician assistants increase primary care utilization in community health centers?

Abstract

Expanding state scope of practice (SOP) for nurse practitioners (NPs) and physician assistants (PAs) can boost productivity and improve access to health care services. Existing analyses on regulatory policies in NP or PA SOP have primarily focused on the direct effects on their own professions but have not fully considered the potential cross-professional effects. This study examines the impact of expanded state SOP for NPs and PAs on primary care utilization by NP, PA, and primary care physician (PCP) in community health centers (CHCs). We conducted a difference-in-differences approach using the Uniform Data System for 739 CHCs from 2009 to 2015. During our study period, 12 states liberalized NP SOP laws and 14 states changed their PA SOP regulations. The number of visits per full-time equivalent clinician (NP, PA, and PCP) per year was the outcome of interest and was linked to the degree of state SOP restriction for NPs and PAs in a given year. Granting independent practice and prescriptive authority for NPs resulted in statistically significant increases in NP visits, and decreases in both PA and PCP visits, for those CHCs with a high proportion of NPs and PAs along with the increased provision of support staff. PA SOP liberalization had no statistically significant effect on PA visits. As the NP and PA workforce continues to grow, and as SOP laws continue to be liberalized, it is important to advance evidence on how to most efficiently deploy these staff.