Association of Formulary Prior Authorization Policies With Buprenorphine-Naloxone Prescriptions and Hospital and Emergency Department Use Among Medicare Beneficiaries

IMPORTANCE: Prior authorization requirements may be a barrier to accessing medications for opioid use disorder treatment and may, therefore, be associated with poor health care outcomes. OBJECTIVE: To determine the association of prior authorization with use of buprenorphine-naloxone and health care outcomes. DESIGN, SETTING, AND PARTICIPANTS: This comparative interrupted time series analysis examined enrollment and insurance claims data from Medicare beneficiaries with an opioid use disorder diagnosis or who filled a prescription for an opioid use disorder medication between 2012 and 2017. Over this period, 775 874 members were in 1479 Part D plans that always required prior authorization, 113 286 members were in 206 plans that removed prior authorization, 189 461 members were in 489 plans that never required prior authorization, and 619 919 members were in 485 plans that added prior authorization. Data analysis was performed from April 2019 to February 2020. EXPOSURES: Removal or addition of prior authorization and new prescriptions filled for buprenorphine-naloxone. MAIN OUTCOMES AND MEASURES: Buprenorphine-naloxone use, inpatient admissions, emergency department visits, and prescription drug and medical expenditures. RESULTS: The study population in 2012 included 949 206 Medicare beneficiaries (mean [SD] age, 57 [15] years; 550 445 women [58%]). Removal of prior authorization was associated with an increase of 17.9 prescriptions (95% CI, 1.1 to 34.7 prescriptions) filled for buprenorphine-naloxone per plan per year, which is a doubling of the number of prescriptions, on average. Each prescription filled was associated with statistically significant decreases in adverse health care outcomes: substance use disorder–related inpatient admissions decreased by 0.1 admission per plan per year (95% CI, −0.2 to −0.1 admission per plan per year), and substance use disorder–related emergency department visits decreased by 0.1 visit per plan per year (95% CI, −0.13 to −0.03 visit per plan per year) (all P < .001). Combining these results, removal of prior authorization was associated with a reduction in substance use disorder–related inpatient admissions by 2.0 admissions per plan per year (95% CI, −4.3 to −0.1 admissions per plan per year) and substance use disorder–related emergency department visits by 1.4 visits per plan per year (95% CI, −3.2 to −0.1 visits per plan per year). CONCLUSIONS AND RELEVANCE: Removing prior authorization for buprenorphine-naloxone was associated with an increase in the medication use and decreases in health care utilization and expenditures.