6983 patients on a national methadone treatment register aged 16 to 65 years between 2004 and 2010 took part in this study to assess whether risk of death increases during periods of treatment transition, and investigate the impact of supervised methadone consumption on drug-related and all cause mortality.

Results: Crude drug-related mortality rates were 0.24 per 100 person-years on treatment and 0.39 off treatment, adjusted mortality rate ratio 1.63. Crude all-cause mortality rate per 100 person-years was 0.51 on treatment versus 1.57 off treatment, adjusted mortality rate ratio 3.64. All-cause mortality off treatment was 6.36 times higher in the first 2 weeks, 9.12 times higher in weeks 3–4, compared with being 5 weeks or more in treatment. All-cause mortality was lower in those with regular supervision (crude mortality rate 0.60 versus 0.81 per 100 person-years) although, after adjustment, insufficient evidence exists to suggest that regular supervision is protective.

Conclusions: Among primary care patients undergoing methadone treatment, continuing in methadone treatment is associated with a reduced risk of death. Patients' risk of all-cause mortality increases following treatment cessation, and is highest in the initial four week period. (This article is protected by copyright. All rights reserved.)