Impact of Nurse Practitioner Scope of Practice Regulation on Access to Care: Implications for Policy & Research from a Systematic Review

Background: Policy reform aimed at removing state-level scope of practice (SOP) restrictions for nurse practitioners (NPs) is debated as a strategy to increase access to care because NPs are the fastest growing primary care (PC) provider, are more likely to provide care for select underserved populations than other provider types, and provide high-quality cost-effective care12,13,14,15. Research Objective: This study was conducted to systematically review literature on the impact of state-level SOP regulations for NPs on access to health care services, as defined by Aday and Andersen’s (1974) Framework for the Study of Access to Medical Care11 Study Design: We searched CINAHL, Pubmed, And EMBASE for studies published from 2006--‐2016 using a comprehensive keyword search strategy. The search yielded 500 studies, of which 8 met inclusion criteria. 2 additional studies were added after the initial review was conducted, yielding 10 total studies. All data were extracted into a standardized template, assessed for themes and categories, and guided by Aday & Andersen’s Framework (1974)11. This framework was further used to examine access to care relationships across reviewed studies. PRIMSA guidelines were followed. Conclusions: The results from this review largely support that less restrictive NP SOP regulations is associated with increased access to care. However, additional research that uses longitudinal methods would better inform recommendations for policy efforts surrounding state level NP SOP regulation. Results: CHARACTERISTICS OF THE HEALTH DELIVERY SYSTEM: NPs were more likely to practice in states with the least SOP restrictions1,3,4,8. Furthermore, there was greater growth in the number of NPs in states with the least SOP regulations4,8. CHARACTERISTICS OF THE POPULATION AT RISK: Some studies report that in states with the least restrictive NP SOP regulations, NPs were more likely to work in PC in rural and high-poverty areas and accept Medicaid1,3. Contrastingly, one study found that rural areas and areas with high poverty rates have fewer NPs, and suggested that this may be due to socioeconomic environment impacting provider reimbursement8. PATIENT LEVEL OUTCOMES: UTILIZATION OF HEATH SERVICES & PATIENT REPORTED QUALITY OF CARE: Patients in states with the least restrictive NP SOP regulations were more likely to use certain preventative services5,6,9,10, have an NP as their PC provider4, have referrals to MDs5, have decreased rates of avoidable hospitalizations, hospital readmissions within 30 days discharge from rehabilitation, hospitalizations of nursing home patients7, emergency room use10, and increased overall health outcomes7. Contrastingly, one study with significant missing data stated that patient reported usual source of care, wait times, and difficulties accessing care were not improved with increased NP SOP regulation2. Furthermore, another study reported that a larger supply of NPs, without considering other state and patient level factors, did not significantly affect healthcare utilization9