Crystal methamphetamine use and methadone maintenance treatment dissatisfaction: A prospective cohort study in Vancouver, Canada.

BACKGROUND: Patient satisfaction is key to the success of methadone maintenance treatment (MMT), and yet how MMT satisfaction is affected by the increasingly common use of crystal methamphetamine among people receiving opioid treatment remains poorly understood. We aimed to assess the association between crystal methamphetamine use and MMT dissatisfaction.

METHODS: We employed generalized estimating equations to examine the relationship between crystal methamphetamine use and MMT dissatisfaction among patients receiving MMT within two prospective cohorts in Vancouver, Canada, between December 2016 and March 2020.

RESULTS: Of the 836 participants receiving MMT, the median age was 47 years, and 55.3 % self-identified as male at baseline. In a multivariable model, those reporting more than weekly crystal methamphetamine use were more likely to report MMT dissatisfaction (Odds ratio: 1.40, 95 % confidence interval: 1.05-1.86) compared to those reporting less than monthly crystal methamphetamine use.

CONCLUSIONS: Among our sample of people receiving MMT, we noted a positive association of frequent crystal methamphetamine use with MMT dissatisfaction. Our study suggests a need for novel strategies to better understand and address frequent methamphetamine use among those receiving MMT, particularly given recent shifts in substance use patterns involving the rising co-use of methamphetamines and opioids.