The Effect of Nurse Practitioner Scope of Practice Laws on Commercially Insured Patients: Evidence from Law Changes

About half of US states require nurse practitioners (NPs) to have a supervision or a collaboration agreement with a physician in order to provide health care services. Whether such constraints benefit patients is unclear. They may protect patients from receiving care in circumstances that would compromise patient safety or merely restrict access to care and reduce competition among providers. We use a commercial insurance claims data set and a difference-in-differences design to estimate the effect of expanding NP scope of practice on health care prices, health care utilization, and proxies for patient health. Prescriptions and outpatient visits are unaffected by expanded scope of practice. There is also no evidence of increased utilization of intensive health care services like emergency department visits and inpatient admissions that would suggest patients are receiving lower quality outpatient care. These results provide little evidence that greater scope of practice benefits patients but also show no evidence of harm.