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IIR 13-063 – HSR&D Study

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IIR 13-063
Nurse Practitioners and Physician Assistants: Primary Care Roles and Outcomes
George Lee Jackson PhD MHA
Durham VA Medical Center, Durham, NC
Durham, NC
Funding Period: July 2014 - June 2017

BACKGROUND/RATIONALE:
Expected primary care provider shortfalls threaten access to care in both the Veterans Health Administration (VHA) and the United States healthcare system. Meanwhile, deficiencies in quality and efficiency of primary care demand new approaches such as patient-aligned care team models. Expanded use of nurse practitioners (NPs) and physician assistants (PAs) offers a potential mechanism for addressing access, quality, and cost issues. Although the VHA has been a pioneer in adopting expansive roles for non-physician providers and VHA patient-aligned care teams (PACTs) can be led by NPs and PAs, there is limited information about how the work of patient care is divided among VHA providers and about how this division of labor affects care outcomes and costs. Because of potential differences in care provided by NPs and PAs, our study assessed each profession separately. We used diabetes as a tracer condition to evaluate care provided by primary care NPs, PAs, and physicians.

OBJECTIVE(S):
The project's purpose was to examine clinical roles of NPs, PAs, and physicians in VHA primary care of patients with diabetes and to assess the association of these roles with care outcomes and costs. The first aim characterized role patterns for allocation of patient care work among NPs, PAs, and physicians in the care of patients with diabetes in VHA primary care clinics. Secondly, we sought to compare quality of care outcomes for patients with diabetes across usual provider of care (UPC) types and NP & PA roles, controlling for organizational characteristics and patient health status. Third, we evaluated patient-level health resource utilization and costs for patients with diabetes across UPC types and NP & PA roles, controlling for initial health and organizational characteristics.

METHODS:
Using retrospective analyses of secondary data, we examined the care of adult, pharmaceutically-treated diabetes patients receiving care at primary care locations within the Veterans Affairs (VA) healthcare system in 2012 and 2013. A patient's usual provider of care was defined as the primary care provider most often visited in the primary care clinic in 2012. This analysis included patients with the same PCP in 2012 and 2013. We described the patterns of care and roles (usual provider vs. supplemental provider; type of care provided, and complexity of patients) of NPs, PAs, and physicians by patient and organizational characteristics. We examined associations between the profession and roles of the UPC and intermediate diabetes outcomes and control, healthcare utilization, and healthcare costs. Hierarchical linear mixed models and logistic regression models were used to analyze continuous and dichotomous outcomes respectively. These analyses accounted for patient and organizational level characteristics potentially associated with diabetes outcomes.

FINDINGS/RESULTS:
Based on data from the VA Corporate Data Warehouse, there were 710,267 patients who met inclusion criteria including 1) an ICD-9 code for diabetes; 2) at least 1 pharmacy fill for diabetes medication in FY 12; 3) at least 2 outpatient visits (or at least 1 inpatient visit) in FY12; 3) at least 1 outpatient visit in FY13; and 4) at least 1 primary care encounter with an MD, NP, or PA in FY12. These Veterans received the largest portion of their primary care from 840 VA clinic locations meeting inclusion criteria. The most frequent primary care providers for patients in the VHA in FY 12 (defined as the primary care provider most frequently seen in that year) were attending physicians (76% of patients), NPs (16% of patients), PAs (6% of patients), and resident physicians (2% of patients). Among the findings, no clinically significant differences were observed between outcomes of patients for physicians, NPs, and PAs. Compared to physicians: 1) mean HbA1c differences were -0.05% (-0.07:-0.03) for NPs and 0.01% (95%CI=-0.02:0.03) for PAs; 2) mean SBP differences were -0.26mmHg (-0.45:-0.07) for NPs and -0.25mmHg (-0.50:0.01) for PAs; and 3) mean LDL-C differences were 1.03mg/dl (0.59:1.48) for NPs and 1.77mg/dl (1.18:2.37) for PAs.

IMPACT:
Both the VHA and broader healthcare system in the United States are seeking ways to expand access to primary care. There has long been debate over the potential roles of non-physician primary care providers in addressing access issues. The VHA has recently expanded the clinical duties of nurse practitioners and continues to consider appropriate clinical roles of physician assistants. The results of this study provided important expanded evidence that NP and PA providers can achieve similar diabetes outcomes among their patients as physicians. As a result, it added to the body of evidence that NPs and PAs can and do have extensive roles in treating patients with chronic illness in primary care settings.

PUBLICATIONS:

Journal Articles

  1. Jackson GL, Smith VA, Edelman D, Hendrix CC, Morgan PA. Intermediate Diabetes Outcomes in Patients Managed by Physicians, Nurse Practitioners, or Physician Assistants. Annals of internal medicine. 2019 Jul 16; 171(2):145.
  2. Everett CM, Morgan P, Smith VA, Woolson S, Edelman D, Hendrix CC, Berkowitz T, White B, Jackson GL. Primary care provider type: Are there differences in patients' intermediate diabetes outcomes? JAAPA : official journal of the American Academy of Physician Assistants. 2019 Jun 1; 32(6):36-42.
  3. Morgan PA, Smith VA, Berkowitz TSZ, Edelman D, Van Houtven CH, Woolson SL, Hendrix CC, Everett CM, White BS, Jackson GL. Impact Of Physicians, Nurse Practitioners, And Physician Assistants On Utilization And Costs For Complex Patients. Health affairs (Project Hope). 2019 Jun 1; 38(6):1028-1036.
  4. Alexopoulos AS, Jackson GL, Edelman D, Smith VA, Berkowitz TSZ, Woolson SL, Bosworth HB, Crowley MJ. Clinical factors associated with persistently poor diabetes control in the Veterans Health Administration: A nationwide cohort study. PLoS ONE. 2019 Mar 29; 14(3):e0214679.
  5. Jackson GL, Smith VA, Edelman D, Woolson SL, Hendrix CC, Everett CM, Berkowitz TS, White BS, Morgan PA. Intermediate Diabetes Outcomes in Patients Managed by Physicians, Nurse Practitioners, or Physician Assistants: A Cohort Study. Annals of internal medicine. 2018 Dec 18; 169(12):825-835.
  6. Everett CM, Morgan P, Smith VA, Woolson S, Edelman D, Hendrix CC, Berkowitz T, White B, Jackson GL. Interpersonal continuity of primary care of veterans with diabetes: a cohort study using electronic health record data. BMC family practice. 2018 Jul 30; 19(1):132.
  7. Morgan P, Everett CM, Smith VA, Woolson S, Edelman D, Hendrix CC, Berkowitz TSZ, White B, Jackson GL. Factors Associated With Having a Physician, Nurse Practitioner, or Physician Assistant as Primary Care Provider for Veterans With Diabetes Mellitus. Inquiry : A Journal of Medical Care Organization, Provision and Financing. 2017 Jan 1; 54:46958017712762.
  8. Everett CM, Morgan P, Jackson GL. Patient characteristics associated with primary care PA and APRN roles. JAAPA : official journal of the American Academy of Physician Assistants. 2016 Dec 1; 29(12):1-6.
VA Cyberseminars

  1. Jackson GL. Differences in Diabetes Outcomes among VA Patients with Nurse Practitioner, Physician Assistant, and Physician Primary Care Providers. VHA Nursing Research Field Advisory Committee Webinar [Cyberseminar]. VHA Nursing Research. 2017 Mar 16.
Conference Presentations

  1. Everett C, Morgan P, Smith V, Woolson S, Edelman D, Hendrix CC, Berkowitz TS, White B, Jackson GL. Interpersonal continuity of primary care of Veterans Health Administration patients with diabetes. Poster session presented at: AcademyHealth Annual Research Meeting; 2016 Jun 27; Boston, MA.
  2. Morgan P, Everett C, Smith V, Woolson S, White C, Hendrix CC, Edelman D, Jackson GL. Correlates of primary care provider type assignment in the Veterans Health Administration. Poster session presented at: AcademyHealth Annual Research Meeting; 2016 Jun 26; Boston, MA.
  3. Crowley M, Edelman D, Berkowitz TS, Smith V, Woolson S, Jackson GL. Characterization of Veterans with Persistently Poor Diabetes Control: Data from a Nationwide Cohort. Poster session presented at: American Diabetes Association Annual Scientific Session; 2016 Jun 12; New Orleans, LA.
  4. Crowley M, Edelman D, Berkowitz TS, Smith V, Woolson S, Jackson GL. Medication Use among Veterans with Persistently Poor Diabetes Control: Data from a Nationwide Cohort. Paper presented at: American Diabetes Association Annual Scientific Session; 2016 Jun 12; New Orleans, LA.
  5. Morgan P, Everett C, Smith V, Woolson S, White BS, Hendrix CC, Edelman D, Jackson GL. Primary Care Provider Type for Veterans with Diabetes. Presented at: Association of American Medical Colleges Annual Meeting; 2016 May 5; Chicago, IL.
  6. Morgan P, Everett C, Smith V, Woolson S, White B, Hendrix CC, Edelman D, Jackson GL. Primary care provider type assignment in the VHA. Poster session presented at: Physician Assistant Education Association National Education Forum; 2015 Oct 14; Minneapolis, MN.
  7. Everett CM, Morgan P, Jackson GL. The Role of Physician Assistants and Advance Practice Nurses in Primary Care: Predictors and Outcomes. Paper presented at: AcademyHealth Annual Research Meeting; 2014 Jun 8; San Diego, CA.


DRA: Health Systems, Diabetes and Related Disorders
DRE: none
Keywords: Best Practices, Care Coordination, Clinical Diagnosis and Screening
MeSH Terms: none

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