Impact of increased criminal penalties for fentanyl possession on initiation and retention on medications for opioid use disorder in Colorado

Abstract

Aims: To assess the impact of HB 22-1326, a state law increasing criminal penalties for fentanyl possession, on buprenorphine and methadone initiation and retention.

Design: Interrupted time series without control SETTING: The state of Colorado PARTICIPANTS: We analyzed Colorado buprenorphine and methadone dispensing data for individuals aged 18-64 years from January 2018 to December 2023.

Intervention: Colorado House Bill 1326 (HB-1326), which increased criminal penalties for fentanyl possession in July 2022.

Measurements: Monthly initiation and 180-day retention rates for buprenorphine and methadone pre- and post-HB 22-1326.

Findings: For buprenorphine initiation rates, there were no statistically significant post-implementation level or slope changes, relative to an increasing pre-implementation trend. Methadone initiation rates showed similarly no statistically significant post-implementation changes, following an increasing pre-implementation trend. For buprenorphine retention rates, there were no statistically significant post-implementation level or slope changes, relative to a flat pre-implementation trend. For methadone retention rates, the post-implementation trend showed a statistically significant slope decrease (5.3% per month; 95% CI = -7.2%, -3.4%), relative to a decreasing pre-implementation trend. However, this finding was not robust in the sensitivity analysis that applied alternative assumptions for missing discharge dates.

Conclusions: Increased criminal penalties for fentanyl possession may not yield meaningful changes in MOUD initiation or retention.

Keywords: Buprenorphine; Drug policy; Interrupted time series; Medications for opioid use disorder; Methadone.