Comparing Physician Assistant and Nurse Practitioner Practice in U.S. Emergency Departments, 2010–2017

Fred Wu, MHS, PA-C; Michael A. Darracq, MD, MPH


Western J Emerg Med. 2021;22(5):1150-1155. 

In This Article

Abstract and Introduction


Introduction: We sought to compare physician assistant (PA) and nurse practitioner (NP) practice in United States emergency departments (ED) based on ED visits as reported by the National Hospital Ambulatory Medical Care Survey (NHAMCS).

Methods: We performed a retrospective, secondary analysis of the 2010 to 2017 NHAMCS with analysis of ED visits, patient demographics, and hospital characteristics.

Results: Between 2010 to 2017, 21.0% (95% confidence interval, [CI] +/−3.1%) of ED visits were seen by either a PA/NP (with and without physician involvement) and 8.6% (+/−2.9%) were seen by PA/NP alone. We identified an increase for NP visits between 2014–2016 and found that PA/NP visits share many of the same characteristics.

Conclusion: While emergency medicine has predominately been a specialty for PAs, the number of ED visits with NPs has been increasing over the past several years. While there are some differences, PAs/NPs share many similar practice characteristics in the ED.


Physician assistants (PA) and nurse practitioners (NP), commonly referred to as advanced practice clinicians, advanced practice providers or midlevel providers, are increasingly being used in US emergency departments (ED) and as a result are causing some controversy. Some have expressed concern that PAs and NPs are replacing emergency physicians with associated financial repercussions. Published literature regarding PA and NP "replacement" is generally anecdotal, without objective data, or applicable analysis.[1–3]

Approximately 14,000 NPs (representing 5.9% of the total US-licensed NPs) practice in the acute care setting according to the American Association of Nurse Practioners.[4] Approximately 13% of certified PAs (which represents over 12,000 PAs) practice emergency medicine (EM).[5] In 2009 an estimated 77.2% of US EDs used PAs and NPs in day-to-day patient care.[6] According to the Emergency Department Benchmarking Alliance, a 39% increase in the use of NPs and PAs was observed between 2010–2016 among US EDs.[7] A secondary analysis of 2014 Medicare data determined that the ED workforce consisted of 58,641 clinicians with 24.5% classified as advanced practice providers; 68.4% of these were PAs, and 31.5% were NPs.[8]

PAs and NPs have different clinical practice pathways.[9] PAs are educated along a medical model similar to US medical students, while NPs are educated along a nursing model.[10] PAs and NPs also have different scopes of practice, practice theories, and educational models.[10,11] Independent practice as described by Full Practice Authority eliminates unnecessary contracts or agreements with physicians, along with elimination of oversight by the state medical board, and is supported by the American Association of Nurse Practitioners.[12] In 2019, 28 states and the District of Columbia granted NPs Full Practice Authority to practice without physician supervision.[13] The American Academy of Physician Assistants also supports the elimination of a legal requirement for a specific relationship between a PA and a physician.[14]

Prior studies analyzing the use of advanced practice or midlevel providers in the ED have not distinguished between NPs and PAs but rather present data in aggregate as "midlevel providers."[6,15,16] These previous studies have not directly compared PA to NP utilization in US EDs. Thus, we believe comparison of these practice pathways in the ED is appropriate given the differences in education; desired scope of practice; practice theories; the absence of previous comparisons of PA and NP utilization in the published literature using National Hospital Ambulatory Medical Care Survey (NHAMCS) data; and the controversy regarding utilization of midlevel providers. We sought to compare PA to NP utilization in US EDs from 2010–2017 using publicly available data from the NHAMCS.[17] Specifically, we sought to compare ED visits with physician involvement (PA with physician, NP with physician) and without physician involvement (PA only, NP only). We analyzed patient demographics and visit and hospital characteristics.