Figure 2. Estimated Change in Buprenorphine Prescriptions per 1000 Medicaid Enrollees Comparing States that Removed Prior Authorization (PA) vs Those That Maintained PAs, 2015-2019.
Percent change estimates come from an event study model that controls for state fixed effects, year fixed effects, and the state-level covariates listed in the Statistical Analysis section. The SEs are clustered at the state level. Using a 2-way fixed-effects difference-in-differences model adjusted for all of the state-level covariates, PA removal was not associated with significant changes in buprenorphine prescriptions per 1000 Medicaid enrollees (−1.4% increase; 95% CI, −31.2% to 41.4%). Solid line indicates percent change; shaded area, 95% CI; dotted line, repeal of PAs for buprenorphine.