The effect of time spent in treatment and dropout status on rates of convictions, cautions and imprisonment over 5 years in a primary care-led methadone maintenance service

Addiction. 2010 Apr;105(4):732-9. doi: 10.1111/j.1360-0443.2009.02856.x.


Background: Methadone maintenance treatment (MMT) in primary care settings is used increasingly as a standard method of delivering treatment for heroin users. It has been shown to reduce criminal activity and incarceration over periods of periods of 12 months or less; however, little is known about the effect of this treatment over longer durations.

Aims: To examine the association between treatment status and rates of convictions and cautions (judicial disposals) over a 5-year period in a cohort of heroin users treated in a general practitioner (GP)-led MMT service.

Design: Cohort study.

Setting: The primary care clinic for drug dependence, Sheffield, 1999-2005.

Participants: The cohort comprised 108 consecutive patients who were eligible and entered treatment. Ninety were followed-up for the full 5 years.

Intervention: The intervention consisted of MMT provided by GPs in a primary care clinic setting.

Measurements: Criminal conviction and caution rates and time spent in prison, derived from Police National Computer (PNC) criminal records.

Findings: The overall reduction in the number of convictions and cautions expected for patients entering MMT in similar primary care settings is 10% for each 6 months retained in treatment. Patients in continuous treatment had the greatest reduction in judicial disposal rates, similar to those who were discharged for positive reasons (e.g. drug free). Patients who had more than one treatment episode over the observation period did no better than those who dropped out of treatment.

Conclusions: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cohort Studies
  • Crime / legislation & jurisprudence
  • Crime / statistics & numerical data*
  • England
  • Family Practice
  • Female
  • Heroin Dependence / rehabilitation*
  • Humans
  • Long-Term Care
  • Male
  • Methadone / therapeutic use*
  • Narcotics / therapeutic use*
  • Patient Dropouts / statistics & numerical data*
  • Practice Guidelines as Topic
  • Prisons / statistics & numerical data
  • Regression Analysis
  • Substance Abuse Treatment Centers*
  • Time Factors
  • Treatment Outcome
  • Young Adult


  • Narcotics
  • Methadone