Nurse Practitioner and Physician Assistant Waivers to Prescribe Buprenorphine and State Scope of Practice Restrictions

There is a shortage of clinicians authorized to prescribe medications to treat opioid use disorder.^1,2 Nurse practitioners (NPs) and physician assistants (PAs) were allowed to obtain waivers to prescribe buprenorphine beginning in 2016.^3,4 We investigated the proportions of NPs and PAs with waivers in 2018 and the association with state regulations that restrict their scope of practice.

We obtained state-level data on the number of Drug Addiction Treatment Act waivers for physicians, NPs, and PAs as of September 2018 from the Substance Abuse and Mental Health Services Administration. The percentages of physicians and NPs with waivers per state were calculated by dividing by the total numbers of licensed physicians and NPs reported in the Area Health Resource File (2016). The percentage of PAs with waivers was calculated by dividing by the number of certified PAs reported by the National Commission on Certification of Physician Assistants (2016).

We measured scope of practice as a binary variable. Less restrictive was defined as whether NPs can prescribe medications without physician oversight⁵ and whether state PA regulations included at least 5 of 6 “essential elements” of practice recommended by the American Association of Physician Assistants (listed in footnote “d” in the Table), which primarily recommend that scope of practice be defined at the practice level rather than being restricted at the state level.⁶

We compared mean proportions of clinicians with waivers per state by clinician type and scope of practice category and computed Pearson correlations of these proportions, weighted by the total numbers of NPs/PAs in the state. Because the percentages of NPs and PAs with waivers were correlated with that of physicians, we estimated weighted least squares regression equations for the proportions of waivered NPs and PAs per state, with scope of practice as the independent variable and the percentage of physicians with waivers as the control variable. Analyses were conducted using Stata-MP (version 15.1; StataCorp), with 2-group T² tests for means and 2-sided t tests for regressions, with significance at P < .05. The study was determined exempt by the University of California, San Francisco Committee for Human Research.

Less restrictive regulations occurred in 27 states for NPs and 23 states for PAs. There were 44 916 physicians (5.57% of all physicians), 7280 NPs (3.17% of NPs), and 1913 PAs (1.66% of PAs) with waivers to prescribe buprenorphine. The correlation between the state-level percentages of physician and NP waivers was 0.8 (P < .001) and between physician and PA waivers was 0.63 (P < .001). The mean percentage of NPs with waivers was 5.58% in less restrictive states and 2.44% in more restrictive states, with a mean difference of 3.14 percentage points (95% CI, 2.05-4.23 percentage points) (Table). Physician assistant scope of practice was not significantly associated with the percentages of PAs and physicians with waivers.

After controlling for the percentage of physicians with waivers using multivariate regression, the adjusted percentage of NPs with waivers was 4.73% in less restrictive states and 2.70% in more restrictive states, with a mean difference of 2.03 percentage points (95% CI, 2.02-2.04 percentage points) (Table). There remained no significant association between less restrictive PA scope of practice and the percentage of PAs with waivers.

Greater practice restrictions were associated with a lower percentage of NPs, but not PAs, with waivers. The difference in NPs with waivers was modest in terms of percentage points, but was more than 75% larger in less restrictive states compared with more restrictive states. Differences in characteristics between NP and PA scope of practice restrictions, such as PA regulations in all states requiring collaboration with a physician, unlike NPs, may explain the result.

Limitations of this study include that the denominators may include nonpracticing clinicians, leading to underestimation of clinicians with waivers, and that NPs and PAs have been able to obtain waivers for only 2 years.

The results of this study suggest that states in which NP practice is restricted may be less able to expand the opioid treatment workforce.

Accepted for Publication: January 25, 2019.

Corresponding Author: Joanne Spetz, PhD, Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco, 3333 California St, Ste 265, San Francisco, CA 94118 (Joanne.Spetz@ucsf.edu).

Author Contributions: Dr Spetz and Mr Toretsky had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Spetz, Tierney, Phoenix, Chapman.

Acquisition, analysis, or interpretation of data: Spetz, Toretsky, Chapman.

Drafting of the manuscript: Spetz, Phoenix, Chapman.

Critical revision of the manuscript for important intellectual content: Spetz, Toretsky, Tierney, Chapman.

Statistical analysis: Spetz, Toretsky.

Obtained funding: Spetz.

Administrative, technical, or material support: Tierney.

Supervision: Spetz, Phoenix.

Conflict of Interest Disclosures: Dr Spetz reported receiving grants from the National Council of State Boards of Nursing during the conduct of the study and personal fees from the Center to Champion Nursing in America (American Association of Retired Persons) and grants from the Robert Wood Johnson Foundation, National Council of State Boards of Nursing, and California Health Care Foundation outside the submitted work. Dr Tierney reported receiving grants from the National Council of State Boards of Nursing’s Center for Regulatory Excellence during the conduct of the study and honoraria from Contemporary Forums, the American Society of Addiction Medicine, Cabezon Group, and the American Psychiatric Nurses Association; grants from the Substance Abuse and Mental Health Services Administration; and honorarium from Johnson & Johnson outside the submitted work. No other disclosures were reported.

Funding/Support: This research was supported by the National Council of State Boards of Nursing’s Center for Regulatory Excellence (grant R101026).

Role of the Funder/Sponsor: The funder was not involved in the design and conduct of the study; collection, management, analysis, and interpretation of the data; or preparation, review, or approval of the manuscript. They approved of the decision to submit the manuscript for publication to JAMA, without review of the manuscript, per the terms of the grant.