Evaluating the impact of community-based treatment options on methamphetamine use: findings from the Methamphetamine Treatment Evaluation Study (MATES)

Aims To evaluate the impact of community‐based drug treatment on methamphetamine use using inverse probability of treatment‐weighted (IPTW) estimators to derive treatment effects. Design A longitudinal prospective cohort study with follow‐ups at 3 months, 1 year and 3 years. Treatment effects were derived by comparing groups at follow‐up. IPTW estimators were used to adjust for pre‐treatment differences between groups. Setting Sydney and Brisbane, Australia. Participants Participants were methamphetamine users entering community‐based detoxification (n = 112) or residential rehabilitation (n = 248) services and a quasi‐control group of methamphetamine users (n = 101) recruited from the community. Measurements Frequency of methamphetamine use between interviews (no use, less than weekly, 1–2 days per week, 3+ days per week), continuous abstinence from methamphetamine use, past month methamphetamine use and methamphetamine dependence. Findings Detoxification did not reduce methamphetamine use at any follow‐up relative to the quasi‐control group. Relative to quasi‐control and detoxification groups combined, residential rehabilitation produced large reductions in the frequency of methamphetamine use at 3 months [odds ratio (OR) = 0.23, 95% confidence interval (CI) 0.15–0.36, P