Association for Public Policy Analysis & Management

Ensuring access to primary care services is a main component of addressing health inequalities and improving health outcomes. However, nation-wide shortages of primary care providers restrict access to needed primary care services. In hopes of increasing the number of primary care providers, states are increasingly passing legislation to expand nurse practitioners’ legal authority, or scope of practice (SOP), to treat and diagnose patients and to prescribe medications. Proponents of expanding NP’s scope of practice view NPs as cost-effective means of addressing the shortage in primary care physicians and claim the requirements for physician oversight are an unnecessary barrier to NP’s ability to function as a patient’s primary care provider. Opponents to the laws argue that the differences in training between a physician and NP jeopardize the ability of NPs to provide safe and effective care in the absence of physician supervision or collaboration. Despite the legislative attention to scope of practice laws, there is little empirical research documenting the impact of these laws on the demand for healthcare services and health outcomes.

I use variation in the timing and passage of SOP laws expanding NPs’ SOP with individual-level data from the 2000 to 2015 Medical Expenditure Panel Survey to determine the effects of these occupational licensing laws on the probability of seeing a NP and multiple measures of prescription demand. Evidence of SOP laws impacting the types of prescriptions filled by patients suggests that expanded authority may lead to different services being provided to patients, suggesting additional avenues through which long-term health outcomes and health care expenditures may be effected by these legislative changes. Understanding these effects are important in light of claims that expanding NPs’ authority jeopardizes patient safety.

The existing research largely explores the impact of expanded SOP on health care utilization irrespective of provider type. This approach may mask the true effects of the laws as NP visits account for a small, but growing, percent of primary care visits (approximately 5%). SOP laws may have large effects on services provided by NPs relative to other providers, yet in data aggregated across all provider types, these effects may not be captured. The few papers which estimate the impact of SOP laws on healthcare utilization and outcomes conditional on provider type are likely to be biased as SOP laws may also affect the probability an individual sees a given provider. I account for simultaneous changes in the type of provider seen during an office-based visit and types of prescriptions filled as NPs gain expanded SOP. The results suggest that granting NPs independent authority increases the probability patients see an NP for primary care without leading to changes in the types of prescriptions filled by patients. These findings add needed evidence to the debate over expanding NPs’ practice and prescribing authority and indicate that expanded authority succeeds in increasing patients’ access to non-physician providers, yet does not have any deleterious effects on the types of services provided.