Retention in Methadone Treatment Reduces the Risk of Death

Patients with opioid use disorder (OUD) have a higher mortality than the general population and treatment has a protective effect. However, an increase in mortality has been noted during treatment transition. In countries where methadone is prescribed in primary care for the treatment of OUD, observed methadone dosing (usually in pharmacies) may also have an impact on mortality. The purpose of this Irish national community-based study was to assess the risk of death during periods of transition off of methadone and the impact of observed methadone dosing on both drug-related deaths and all-cause mortality among 6983 patients aged 19–65 on a national methadone register, 2004–2010.

• Crude drug-related mortality rates were 0.24 per 100 person-years on methadone treatment versus 0.39 off treatment (adjusted mortality rate ratio [aRR], 1.63). Crude all-cause mortality rate per 100 person-years was 0.51 on treatment versus 1.57 off treatment (aRR, 3.64).
• Mortality was highest within the first 4 weeks off treatment:
  • 6 times higher in the first 2 weeks off treatment.
  • 9 times higher weeks 3–4 off treatment.
• All-cause mortality was lower with observed dosing but did not reach statistical significance in the adjusted models.

Comments:

Although this study was underpowered to specifically assess drug related deaths, it confirms some important trends noted in other studies. This includes the increased risk of all-cause mortality after methadone cessation (especially within the first 4 weeks after stopping methadone treatment). This study has implications for providers and policymakers regarding the importance of treatment retention.

Jeanette M. Tetrault, MD

Reference:

Cousins G, Boland F, Courtney B, et al. Risk of mortality on and off methadone substitution treatment in primary care: a national cohort study. Addiction. 2015 [Epub ahead of print]. doi: 10.1111/add.13087.