Huiru Dong1, Kanna Hayashi2, M-J Milloy3, Kora DeBeck4, Joel Singer5, Hubert Wong5, Evan Wood3, Thomas Kerr6. 1. British Columbia Centre on Substance Use, 400-1045 Howe Street, Vancouver, British Columbia V6Z 2A9, Canada; School of Population and Public Health, University of British Columbia, 2206 E Mall, Vancouver, British Columbia V6T 1Z3, Canada. 2. British Columbia Centre on Substance Use, 400-1045 Howe Street, Vancouver, British Columbia V6Z 2A9, Canada; Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada. 3. British Columbia Centre on Substance Use, 400-1045 Howe Street, Vancouver, British Columbia V6Z 2A9, Canada; Department of Medicine, University of British Columbia, 317-2194 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada. 4. British Columbia Centre on Substance Use, 400-1045 Howe Street, Vancouver, British Columbia V6Z 2A9, Canada; School of Public Policy, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada. 5. School of Population and Public Health, University of British Columbia, 2206 E Mall, Vancouver, British Columbia V6T 1Z3, Canada; Centre for Health Evaluation & Outcome Sciences, 1081 Burrard Street, Vancouver, British Columbia V5Z 1Y6, Canada. 6. British Columbia Centre on Substance Use, 400-1045 Howe Street, Vancouver, British Columbia V6Z 2A9, Canada; Department of Medicine, University of British Columbia, 317-2194 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada. Electronic address: bccsu-tk@bccsu.ubc.ca.
Abstract
BACKGROUND: Although previous studies have shown that opioid agonist therapy (OAT) is linked to reductions in illicit opioid use, less is known about how OAT impacts the use of other psychoactive substances. We aimed to examine the changes in use of different substances by comparing patterns before and after initiating OAT. METHODS: Data for this study was derived from three ongoing prospective cohorts involving people who use drugs in Vancouver, Canada from 1996 to 2018. We assessed use patterns for heroin, illicit prescription opioid, cocaine, crack cocaine, crystal methamphetamine, cannabis, daily alcohol use, and benzodiazepines. Segmented regression was conducted to compare the trends of substance use between pre-treatment and post-treatment periods. RESULTS: The study included 1107 participants. After OAT engagement, we observed an immediate decline in the proportion as well as a decreasing trend for heroin (Adjusted Odds Ratio (AOR): 0.80, 95% confidence interval (CI): 0.77, 0.83), illicit prescription opioid (AOR: 0.87, 95% CI: 0.83, 0.90), and benzodiazepines (AOR: 0.73, 95 % CI: 0.67, 0.80). There was no significant difference comparing the pre-treatment and post-treatment trends for cocaine, crack cocaine, crystal methamphetamine, and cannabis. However, higher growth slope was noted during the post-treatment period for daily alcohol use (P = 0.016). CONCLUSIONS: We observed significant reduction in illicit opioids use following OAT initiation, but not for stimulant and cannabis. The increasing problematic use of alcohol may pose challenges to the safety and effectiveness of OAT. Development of comprehensive and tailored treatment strategies is needed for poly-substance users accessing OAT.
BACKGROUND: Although previous studies have shown that opioid agonist therapy (OAT) is linked to reductions in illicit opioid use, less is known about how OAT impacts the use of other psychoactive substances. We aimed to examine the changes in use of different substances by comparing patterns before and after initiating OAT. METHODS: Data for this study was derived from three ongoing prospective cohorts involving people who use drugs in Vancouver, Canada from 1996 to 2018. We assessed use patterns for heroin, illicit prescription opioid, cocaine, crack cocaine, crystal methamphetamine, cannabis, daily alcohol use, and benzodiazepines. Segmented regression was conducted to compare the trends of substance use between pre-treatment and post-treatment periods. RESULTS: The study included 1107 participants. After OAT engagement, we observed an immediate decline in the proportion as well as a decreasing trend for heroin (Adjusted Odds Ratio (AOR): 0.80, 95% confidence interval (CI): 0.77, 0.83), illicit prescription opioid (AOR: 0.87, 95% CI: 0.83, 0.90), and benzodiazepines (AOR: 0.73, 95 % CI: 0.67, 0.80). There was no significant difference comparing the pre-treatment and post-treatment trends for cocaine, crack cocaine, crystal methamphetamine, and cannabis. However, higher growth slope was noted during the post-treatment period for daily alcohol use (P = 0.016). CONCLUSIONS: We observed significant reduction in illicit opioids use following OAT initiation, but not for stimulant and cannabis. The increasing problematic use of alcohol may pose challenges to the safety and effectiveness of OAT. Development of comprehensive and tailored treatment strategies is needed for poly-substance users accessing OAT.
Authors: Marion Selfridge; Kiffer Card; Taylor Kandler; Erin Flanagan; Emily Lerhe; Ash Heaslip; Anne Nguyen; Matthew Moher; Bernie Pauly; Karen Urbanoski; Chris Fraser Journal: Int J Drug Policy Date: 2022-05-04
Authors: Kevin Y Xu; Ned Presnall; Carrie M Mintz; Jacob T Borodovsky; Nisha R Bhat; Laura J Bierut; Richard A Grucza Journal: JAMA Netw Open Date: 2021-02-01