Nurse practitioner scope of practice and opioid prescribing
Publication id: shakya-2024-np-sop-opioid-prescribing
Status: verified
Citation: Shakya, S., & Plemmons, A. (2024). Scope of practice and opioid prescribing behavior of nurse practitioners serving Medicare beneficiaries. Health Economics. Download PDF
Facts¶
Policy hook¶
Policymakers seek to expand healthcare access by increasing nurse practitioner autonomy and prescriptive authority, particularly for Schedule II controlled substances (opioids and other drugs). Critics worry that allowing NPs to prescribe without physician oversight could increase opioid overprescribing and compromise patient safety. The policy question is whether removing physician supervision affects NP prescribing behavior for opioids and non-opioid medications.
Main finding¶
Scope-of-practice expansions do not compromise quality and safety in terms of opioid prescribing behavior. When nurse practitioners gain full autonomy and move from physician-supervised states to full-practice states, their opioid prescribing patterns remain unchanged. Differences in opioid claims, drug costs, days supplied, beneficiary counts, and prescription rates are all statistically insignificant between treatment and comparison groups. Similar null results appear for long-acting opioids, antibiotics, and aggregate prescriptions.
Data and setting¶
Medicare Part D Prescriber Summary Table files, 2013–2021, covering all nurse practitioners serving Medicare beneficiaries with Part D prescriptions. Classification of state scope-of-practice regimes from McMichael and Markowitz (2023), distinguishing states with “Full Autonomy” (independent Schedule II prescriptive authority, no physician oversight) versus “Reduced Scope-of-practice” states (Schedule II prescriptive authority but physician supervision required). Outcomes include claim counts, drug costs, days supplied, beneficiary counts, and prescription rates for opioids and other medications.
Research design (plain language)¶
The paper uses nurse practitioner interstate mobility as a source of plausibly exogenous policy variation. Treatment group: NPs moving from Reduced Scope-of-practice to Full Autonomy states. Comparison group: NPs moving from Reduced Scope-of-practice to another Reduced Scope-of-practice state. Difference-in-differences framework compares prescribing behavior before and after the move across both groups. Event studies and robustness checks (policy reversal, covariates, placebo tests) confirm null results.
One caveat¶
Results are based on relatively small sample sizes of NPs moving each year. The design identifies effects under the assumption that interstate NP mobility is plausibly exogenous to prescribing preferences—NPs move for job autonomy or personal reasons, not to prescribe differently. The analysis cannot resolve whether null effects reflect true absence of behavioral change or limited statistical power to detect small effects.
PDF or DOI¶
Why it matters¶
The opioid crisis has created conflicting policy pressures: expanding healthcare access while preventing overprescribing. Scope-of-practice restrictions are sometimes defended as patient safety guardrails, with the concern that unsupervised NPs will prescribe opioids irresponsibly. This paper provides empirical reassurance that expanding NP autonomy does not compromise prescribing safety in terms of opioid behavior. When NPs gain full prescribing authority without physician oversight, their opioid prescribing patterns, claim frequencies, drug costs, and patient counts remain statistically unchanged from supervised practice. The null result holds for long-acting opioids (which carry higher abuse risk) and for non-opioid medications, suggesting broad consistency in prescribing practice across regulatory regimes. For policymakers, the findings offer evidence that scope expansion can increase healthcare access without the feared downstream increase in opioid dispensing. However, the modest sample sizes warrant caution—true effects may be small but real. The results support removing restrictive oversight rules as one component of addressing primary care shortages while maintaining patient safety through other mechanisms (education, peer feedback, PDMP monitoring).