Do interruptions to the continuity of methadone maintenance treatment in specialist addiction settings increase the risk of drug‐related poisoning deaths? A retrospective cohort study

• DOI: 10.1111/add.15004
• Publication Date: 2020-02-08T06:09:58Z
• Authors: Louise Durand; Denis O'Driscoll; Fiona Boland; Eamon Keenan; Benedict K. Ryan; Joseph Barry; Kathleen Bennett; Tom Fahey; Gráinne Cousins
• Keywords: Methadone maintenance

Abstract Aims To examine the risk of mortality associated with interruptions to continuity methadone maintenance treatment (MMT), including transfers between services, in opioid‐dependent individuals attending specialist addiction services. Design Retrospective cohort study using services and primary care dispensing records, National Methadone Register Drug‐Related Death Index (NDRDI). Setting Geographically defined population Dublin, Ireland. Participants A total 2899 people prescribed dispensed January 2010 December 2015. There were five exposure groups: weeks 1–4 following transfer providers; out treatment; 5–52 initiation; 5+ continuous (reference category). Measurements Primary outcome: drug‐related poisoning (DRP) deaths. Secondary all‐cause (ACM). Mortality rates calculated by dividing number deaths (DRP; ACM) groups person‐years exposure. Unadjusted adjusted Poisson regression (covariates age, sex, incarceration, dose comorbidities) estimated differences rates. Findings 154 ACM deaths, 55 (35.7%) identified as DRP No observed first month providers. The was highest [adjusted relative (aRR = 4.04, 95% confidence interval (CI) 1.43–11.43, P 0.009] initiation (ARR 3.4, CI 1.2–9.64, 0.02). Similarly, 11.78, 7.73–17.94, < 0.001), 5.11, 2.95–8.83, 0.001) off 2.04, 1.2–3.47, 0.009). Conclusions Interruptions provider do not appear be periods for or Risk drug related appears greatest during 4 initiation/re‐initiation after cessation.