Nurse Practitioners, Physician Assistants, and Physicians Are Comparable in Managing the First Five Years of Diabetes

Am J Med. 2018 Mar;131(3):276-283.e2. doi: 10.1016/j.amjmed.2017.08.026. Epub 2017 Sep 8.


Background: Increasing use of nurse practitioners and physician assistants is a possible solution to the shortage of primary care providers in the United States, but the quality of care they provide is not well understood.

Methods: Because the scope of practice of the 3 provider types is similar in the Veterans Health Administration, we determined whether patients managed by primary care nurse practitioners, physician assistants, or physicians had similar hemoglobin A1c levels at comparable times in the natural history of diabetes. Our retrospective cohort study examined veterans with newly diagnosed diabetes in 2008, continuous primary care from 2008 to 2012, and more than 75% of primary care visits with nurse practitioner, physician assistant, or physician.

Results: Of the 19,238 patients, 95.3% were male, 77.7% were white, and they had a mean age 68.5 years; 14.7%, 7.1%, and 78.2% of patients were managed by nurse practitioners, physician assistants, and physicians, respectively. Median hemoglobin A1c was comparable at diagnosis (6.6%, 6.7%, 6.7%, P > .05) and after 4 years (all 6.5%, P > .5). Hemoglobin A1c levels at initiation of the first (7.5%-7.6%) and second (8.0%-8.2%) oral medications for patients of nurse practitioners and physician assistants compared with that of physicians was also similar after adjusting for patient characteristics (all P > .05). Nurse practitioners started insulin at a lower hemoglobin A1c (9.4%) than physicians (9.7%), which remained significant after adjustment (P < .05).

Conclusions: At diagnosis and during 4 years of follow-up, diabetes management by nurse practitioners and physician assistants was comparable to management by physicians. The Veterans Health Administration model for roles of nurse practitioners and physician assistants may be broadly useful to help meet the demand for primary care providers in the United States.

Keywords: Diabetes; Midlevel providers; Nurse practitioner; Physician assistant; Primary care.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Diabetes Mellitus / blood
  • Diabetes Mellitus / diagnosis
  • Diabetes Mellitus / therapy*
  • Female
  • Glycated Hemoglobin A / metabolism
  • Humans
  • Hypoglycemic Agents / therapeutic use
  • Insulin / therapeutic use
  • Male
  • Middle Aged
  • Nurse Practitioners*
  • Physician Assistants*
  • Primary Health Care / organization & administration*
  • Retrospective Studies
  • United States
  • Veterans


  • Glycated Hemoglobin A
  • Hypoglycemic Agents
  • Insulin