(P-326) The Effect of Prescriber, Treatment, and Client Characteristics on Retention in Opioid Agonist Treatment: A 15-year Retrospective Cohort Study

Location: Poster Gallery-Health Economics/Outcomes Research

Presenting Author(s)

CB

Chrianna Bharat

University of New South Wales
Randwick, New South Wales, Australia

Co-Author(s)

SL

Sarah Larney

Université de Montréal and Centre de Recherche du CHUM, Montreal, Canada, Quebec, Canada
SB

Sebastiano Barbieri

Centre for Big Data Research in Health, UNSW Sydney, Sydney, Australia, Australia
TD

Timothy Dobbins

School of Population Health, UNSW Sydney, Sydney, Australia, Australia
NJ

Nicola R Jones

National Drug and Alcohol Research Centre, UNSW Sydney, Sydney, Australia, Australia
MH

Matthew Hickman

Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK, United Kingdom
NG

Natasa Gisev, PhD

University of New South Wales
Randwick, New South Wales, Australia
RA

Robert Ali

Department of Pharmacology, University of Adelaide, Adelaide, Australia, Australia
LD

Louisa Degenhardt

National Drug and Alcohol Research Centre, UNSW Sydney, Sydney, Australia, Australia

Background: Evidence for factors impacting opioid agonist treatment (OAT) retention mostly relate to client and treatment characteristics, with limited research considering characteristics of OAT prescribers (e.g., tenure of OAT prescribing, peer group size).

Objectives: This study summarises retention in buprenorphine and methadone treatment for opioid dependence and examines its relationship with prescriber, treatment, and client characteristics among a 15-year retrospective longitudinal cohort of individuals entering OAT for the first time.

Methods:

Design: Retrospective longitudinal study.

Setting: New South Wales, Australia.

Participants: First-time OAT clients (August 2001-December 2015), defined as having never entered the OAT program before August 2001.

Measurements: The primary outcome, time in OAT, was modelled using a generalised estimating equation model to explore associations with prescriber, treatment, and client characteristics.

Results: The impact of medication type on OAT retention reduced over time; risk of leaving treatment when on buprenorphine compared to methadone was higher among those that entered OAT earlier (e.g. 2001-2003: OR 1.59, 95% CI 1.44-1.74) and lowest among those that entered most recently (2013-2015: OR 1.24, 95% CI 1.12-1.37). In adjusted analyses, risk of leaving was reduced among clients whose prescriber had greater tenure of OAT prescribing (e.g. 3 versus 8 years: OR 0.94, 95% CI 0.93-0.95). Aboriginal and Torres Strait Islander peoples, being of younger age, past-year psychosis disorder, and having been convicted of more criminal charges in the year prior to OAT entry were associated with increased risk of leaving OAT.

Conclusions: Retention in buprenorphine compared to methadone has continued to improve with time since its introduction to the program. OAT retention is affected not only by characteristics of the client and their treatment, but also of their OAT prescriber. Greater education and training to support OAT prescribers are possible strategies to improve retention for clients prescribed buprenorphine and methadone.