Estimating the Effect of the New York State Nurse Practitioners Modernization Act on Care Received by Medicaid Patients.

The demand for primary care services may surpass the supply of primary care providers, exacerbating challenges with access, quality, and cost in the U.S. health care system. Expanding the supply of, and access to, nurse practitioner (NP) care has been proposed as one method to alleviate these challenges. New York State (NYS) changed its regulatory environment for NPs in 2015. We estimate the impact of expanded NP scope of practice (SOP) regulations in NYS on total care days received by Medicaid beneficiaries from 2015 to 2018 using a model derived from national historical data from 1999 to 2011. We used a longitudinal data policy analysis framework and a generalized difference-in-differences model to identify the effect of changes in NP SOP regulations on total care days. The model included controls for state income and unemployment rates. Our results suggest that the policy change increased total care days provided to patients, but that this difference was not statistically significant and became negligible after computing the number of days per beneficiary. In addition, our results suggest that had NYS moved to a full practice environment, more care days could have been provided to Medicaid patients, and this difference was found to be statistically significant. Our results suggest that states should adopt full NP SOP practice environments to realize measurable benefits of expanded NP SOP.