Abstract
INTRODUCTION: Elimination of the X-waiver, which required clinicians to complete additional registration to prescribe buprenorphine for opioid use disorder, removed one barrier to treatment. This study examined the association of the X-waiver elimination with buprenorphine dispensations by clinician specialty. METHODS: Using IQVIA Longitudinal Prescription data, patients with 15 or more days of dispensed buprenorphine supply each month from May 2021 to December 2024 were identified. Interrupted time series analyses (conducted in 2025) examined changes in monthly counts of clinicians associated with dispensations and patients, overall and stratified by clinician specialty. RESULTS: During the study period, 189,771 clinicians dispensed buprenorphine to 2,699,441 patients. X-waiver elimination was associated with significant increases in the number of clinicians associated with dispensed buprenorphine prescriptions overall (change in level= 1,626 clinicians; 95% CI=577, 2,674; p<0.01; change in slope: 15 clinicians per month, 95% CI=13, 18, p<0.001) and across all specialties. X-waiver elimination was associated with a decrease in the number of patients with buprenorphine dispensations in January 2023 overall (change in level= -24,104 patients; 95% CI= -40,010, -8,198; p<0.01) and from all clinician groups except behavioral health physicians. Decreasing monthly rates of patients with buprenorphine dispensed by behavioral health physicians slowed after X-waiver elimination; monthly rates of buprenorphine patients with dispensations from primary care providers increased after (versus before) the policy change. CONCLUSIONS: Although the number of clinicians associated with dispensed buprenorphine prescriptions after X-waiver elimination increased across all clinician types, patient-level gains associated with X-waiver elimination were limited.