Where’s the Beef (Part 1): A critique one study at a time on nurse practitioner full practice authority model vs. physician supervision/collaboration model

So I’ve seen several trends in the non-scientific literature (news articles, blogs, social media etc) on the topic of nurse practitioner (NP)/physician assistant (PA) full practice authority (FPA) versus physician collaboration and/or supervision. I support the use of NPs/PAs on Physician led multidisciplinary teams. I have written on this before that utilized correctly these mid-level providers (of which I was one for 8 years as a Psych NP) can add value to healthcare teams. There is great work being done by a great many. However this often becomes an emotionally charged topic such that rational objective discussion is often overshadowed by slander and insults. You often hear proponents of FPA state “evidence shows……” and then this is either not cited or cite a deficient, weak, or methodologically flawed study. You often hear these same proponents when pressed about this, challenge you to “show me your evidence that shows….” which is often followed by something impossible or flawed such as “NPs are inferior…” or “your outcomes are superior…..” etc. Often forgotten or conveniently left out of the discussion is the notion that one discipline is nursing and the other discipline is medicine. Different disciplines. Proponents of the physician collaboration and supervision model will point out that you can’t compare apples to oranges. That you can’t replace apples with oranges and get apple juice. The quote of “where’s the beef”is a parody on this whole discussion of evidence. Where is the evidence? What is the evidence? i.e. “the beef.” Here’s a study by Lohr, Robert H. et al,1and I’ll jump right to the conclusion which states:

“The quality of referrals to an academic medical center was higher for physicians than for NPs and PAs regarding the clarity of the referral question, understanding of pathophysiology, and adequate prereferral evaluation and documentation.”

This conclusion will be lauded by opponents to FPA and scorned by the proponents of FPA. What does it really tell you and what does it really mean? Well, the study’s objective was to “To compare the quality of referrals of patients with complex medical problems from nurse practitioners (NPs), physician assistants (PAs), and physicians to general internists.”The methodology was a retrospective comparison study involving regional referrals to an academic medical center from January 1, 2009, through December 31, 2010. You have to question as to if the findings would be similar in 2019. The study compared 160 referrals by the PA/NP group and 160 referrals by physicians. Both proponents and opponents of FPA might say that the power of the study would increase with a larger sample size. The study utilized a 7-item instrument to assess the quality of referrals spread out among 5 experienced and blinded physicians doing the rating. The results were then analyzed by using multivariate ordinal logistical regression adjusted for patient age, sex, distance of the referral source from Mayo Clinic, and Charlson Index. Interrater reliability was 0.92 overall. Internal consistency was rated as excellent with Cronbach alpha at 0.75. The 7 items were scored as follows:

  1. referral question clearly articulated with MDs at 86.3% to NPs at 76% with P=.0007.
  2. clinical information provided with MDs at 72.6 % to NPs at 54.1% with a P=.003.
  3. documented understanding of the patient’s pathophysiology with MDs at 51% to NPs at 30.3 % with a P<.0001
  4. appropriate evaluation performed locally with MDs at 60.3% to NPs at 39% with a P <.0001.
  5. appropriate management performed locally with MDs at 53.5% to NPs at 24.1% with a P <.0001.
  6. confidence returning patient to referring health care professional with MDs at 67.8% to NPs at 41.4% with a P<.0001. 
  7. evaluated as having been unnecessary with MDs at 30.1% to NPs at 56.2% with a P<.0001

The study assumption was that NPs and PAs can perform the roles of primary care physicians. Also that that primary care physicians have difficulty caring for patients with multiple interacting diseases, which implies that NPs and PAs might also struggle with managing such patients. 

Though the findings seem to support opponents of FPA, they ”indicate the need for future studies to compare patient referrals by physicians, NPs, and PAs with respect to higher-level outcomes such as patient satisfaction and quality of care metrics, as well as research into optimal interdisciplinary models for teams involving physicians, NPs, and PAs.” The findings also suggest that all patient referrals from primary care practices could improve in quality, however those that use NPs and PAs, by involving integrated health care teams that combine the skills of physicians, NPs, and PAs.


  1. Lohr, Robert H. et al. (2013) Comparison of the Quality of Patient Referrals From Physicians, Physician Assistants, and Nurse Practitioners.” Mayo Clinic Proceedings , Volume 88 , Issue 11 , 1266 – 1271

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