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Impact of supervision of methadone consumption on deaths related to methadone overdose (1993-2008): analyses using OD4 index in England and Scotland

BMJ 2010; 341 doi: (Published 16 September 2010) Cite this as: BMJ 2010;341:c4851
  1. John Strang, professor of the addictions1,
  2. Wayne Hall, NHMRC Australia fellow and professor of public health policy2,
  3. Matt Hickman, reader in public health and epidemiology3,
  4. Sheila M Bird, senior scientist4, visiting professor5
  1. 1Kings College London, National Addiction Centre, Institute of Psychiatry, London SE5 8BB, UK
  2. 2School of Population Health, University of Queensland, Australia
  3. 3Social Medicine, University of Bristol, Bristol, UK
  4. 4MRC Biostatistics Unit, Cambridge, UK
  5. 5Department of Mathematics and Statistics, Strathclyde University, Strathclyde, UK
  1. Correspondence to: J Strang john.strang{at}
  • Accepted 15 July 2010


Objective To evaluate the impact of introduction of supervision of methadone dosing on deaths related to overdose of methadone in Scotland and England between 1993 and 2008 while controlling for increased prescribing of methadone.

Design Analysis of annual trends in deaths related to overdose of methadone in relation to defined daily doses of methadone prescribed.

Setting Scotland and England.

Population Deaths in which methadone was coded as the only drug involved or as one of the drugs implicated.

Main outcome measure Annual OD4-methadone index (number of deaths with methadone implicated per million defined daily doses of methadone prescribed in that year).

Results OD4-methadone declined substantially over the four epochs of four years between 1993 and 2008. It decreased significantly (P<0.05) in 10 of 12 epoch changes: in Scotland from 19.3 (95% confidence interval 15 to 24) to 4.1 (2.8 to 5.4) and finally to 3.0 (2.4 to 3.5) for methadone only deaths (and from 58 to 29 to 14 for deaths with any mention of methadone); in England from 27.1 (25 to 29) to 24.8 (23 to 27) and finally to 5.8 (5.3 to 6.3) for methadone only deaths (and from 46 to 42 to 12 for deaths with any mention of methadone). The decreases in OD4-methadone were closely related to the introduction of supervised dosing of methadone in both countries, first in Scotland (1995-2000) and later in England (1999-2005). These declines occurred over periods of substantial increases in prescribing of methadone (18-fold increase in defined daily doses per million population annually in Scotland and sevenfold increase in England).

Conclusions Introduction of supervised methadone dosing was followed by substantial declines in deaths related to overdose of methadone in both Scotland and England. OD4-methadone index analyses, controlled for substantial increases in methadone prescribing in both countries, identified at least a fourfold reduction in deaths due to methadone related overdose per defined daily dose (OD4-methadone) over this period.


  • The General Register Office Scotland (deaths, Scotland), Office for National Statistics (deaths, England), and information services NHS Scotland and England (prescription data) helpfully did special retrievals of national data. We are grateful to John Witton for help with securing these data.

  • Contributors: JS had the idea for the OD4 index and did preliminary investigative analyses; these were refined and improved in discussions with WH, MH, and SMB. JS led on obtaining the data and preparing the first draft of the manuscript, and all authors contributed actively to further development and revision. JS is the guarantor.

  • Funding: None.

  • Competing interests: All authors have completed the Unified Competing Interest form at (available on request from the corresponding author) and declare that (1) JS, WH, MH, and SMB have not received any funding support from any company or organisation for the submitted work; (2) JS, WH, MH, and SMB have no relationships with any company that might have an interest in the submitted work in the previous 3 years; (3) their spouses, partners, or children have no financial relationships that may be relevant to the submitted work; and (4) JS, WH, MH, and SMB have no non-financial interests that may be relevant to the submitted work.

  • Ethical approval: Not needed (analyses of public data).

  • Data sharing: No additional data available.

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