MMT delivered in a primary care clinic setting is effective in reducing convictions and cautions and incarceration over an extended period. Continuous treatment is associated with the greatest reductions.

Administration of an opiate via intravenous injection was the most consistent factor associated with these deaths over the period of this study. Co-administration of other central nervous system depressants, at least in lower quantities appear to be a feature rather than a risk factor per se in such fatalities.