Who dies on methadone treatment- case control study of risks and causes of death amongst people registered in treatment?

First published: 10 May 2019 | Last updated: 20 May 2019

Dr Edyta Truszkowska

Work carried out: National Drug Treatment Centre McCarthy Centre, 30-31 Pearse Street, Dublin 2, Ireland

Funding: The authors declare there was no conflict of interest.

Clinical trial reg:


Abstract: Introduction and Aims

International studies indicate that methadone maintenance treatment (MMT) reduces mortality in opioid dependent patients, but mortality remains elevated compared to the general population. This study aimed to review risk factors impacting upon mortality among patients on MMT.

Design and Method

The study was conducted at an addiction treatment clinic with about 450 patients on MMT. We utilised case-control design matching all deaths occurring between February 2005 and February 2012 with another attendee in terms of age and gender.


There were 80 deaths with median age 35 year. The causes of death were categorised as poisoning (48%), medical (36%) and trauma (16%). Their median methadone dose was 80mg (IQR 60-90) was not significantly different from the control group (median 75mg, IQR65-90, p=0.6). There was no significant difference between the fatalities and the controls in terms of recent misuse of cocaine. Patients who died were more likely to have a history of imprisonment (71% versus 35%, p<0.001), HIV infection (29% versus 12%, p=0.001) and non-HIV related medical problems (47% versus 16%, p<0.001). They were more likely to have missed attendance at the clinic for at least one week (23% versus 1%, p<0.001).

Discussion and Conclusions

Methadone dose was not associated with increased mortality. Our findings indicate that a life history of imprisonment (not only recent release) is a marker for increased risk of death while on MMT. Treatment non-attendance was associated with increased mortality, and services should seek to proactively follow-up on patients who drop out of treatment.


Dr Pavel Konovalov – MD, PhD, DCP, National Drug Treatment Centre, Dublin, Ireland Dr Tahir Galander – MRCPsych, MB BS, National Drug Treatment Centre, Dublin, Ireland Dr Suzi Lyons- Senior Researcher, Health Research Board, Ireland Dr Eamon Keenan – MRCPsych MB BCh, Consultant in Addiction Psychiatry, HSE Addiction Services, Bridge House, Cherry Orchard Hospital, Dublin 10, Ireland Dr Bobby P Smyth – MRCPsych MB BCh BAO, Consultant Child & Adolescent Psychiatrist, Department of Public Health & Primary Care, Trinity College, Dublin


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Dr Edyta Truszkowska