fbpx PREFER | NDARC - National Drug and Alcohol Research Centre


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Date Commenced:
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Drug Type:
Project Members: 
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Ph EA Tori Barnes: 02 9385 0292 / t.barnes@unsw.edu.au
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Deputy Director, NDARC and Program Lead, Drug Trends
Ph +61 (2) 9385 0333
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Clinical Trials Manager
Ph +61 (2) 9385 9984
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Adjunct Lecturer
Ph +61 2 9065 7669
Project Main Description: 


There is increasing emphasis on patient preference and choice in healthcare, however many trials that have examined the effect of preference have had inconclusive findings in regard to clinical outcomes, much of which can be explained by study eligibility, treatment comparisons, or in study design. Further, the increasing number of OAT options means the choice of which to initiate is a preference-sensitive decision. Innovative study design is needed, which supports informed decision making but separates preference effects from direct treatment effects on outcomes.

The PREFER study aims to evaluate patient preferences for opioid agonist treatment (OAT) in Australia among people who regularly use opioids. The study also seeks to also understand factors associated with preferences for different types of opioid agonist treatment.

PREFER is a cross-sectional cohort study of people who regularly use opioids.



Project Collaborators: External: 

Professor Jason Grebely, The Kirby Institute, UNSW sydney

Anna Conway,  The Kirby Institute, UNSW Sydney

Jodi Van Dyk,  The Kirby Institute, UNSW Sydney

Fredrick Altice, Yale University

Denise Esserman, Yale University

Tom Hassett, Yale University



Illicit drug use is one of the largest risk factors for burden of disease worldwide and it is increasing. Among adults aged 15-49 years it is the 6th largest risk factor globally (greater than tobacco smoking); in Australia, it is the biggest. Opioid dependence and injecting drug use account for the greatest burden attributable to illicit drug use. In Australia, opioid deaths have increased by 50% in the past decade overdoses now account for more deaths than traffic accidents.

 Methadone and buprenorphine are established as effective opioid agonist treatment (OAT) for opioid dependence and classed as essential medicines for this indication by the World Health Organization5. Systematic reviews, many conducted by members of our team, have demonstrated they are highly effective in reducing illicit opioid use, HIV and HCV incidence, criminal activity, overdose, and mortality. Despite this, global OAT coverage is low (16% in 2017).

Suboptimal OAT coverage may relate to the way in which it is delivered, impacting accessibility, attractiveness, affordability and cost (for patients and systems). Australian emphasis on supervised daily dosing means many clients must travel significant distances each day, affecting capacity to engage in other activities including employment, increasing stigma, and deterring some from entering treatment. Access in rural/regional areas is difficult, given low prescriber numbers and lengthy distances. Many must pay out-of-pocket dosing fees to pharmacies and private clinics, presenting another barrier to treatment. Daily dosing is a costly service model of delivering OAT, occupying considerable staff time, though daily clinical contact may assist some in structuring daily life.

Recently developed extended-release buprenorphine formulations (XR-BPN) could transform OAT. They are administered by subcutaneous injection, slowly releasing buprenorphine over the dosing interval, which can last a month. Only two US randomised-controlled trials, of two separate formulations, have been published, both company-sponsored for registration purposes. One formulation was superior to placebo17 and the other similar to sublingual buprenorphine in reducing illicit opioid use. Both trials required weekly clinic attendance, so there are no data on the benefits of XR-BPN as it would be delivered in usual practice; neither study had a cost-effectiveness analysis. Extended follow-up involving trial participants showed marked variation in treatment retention.

XR-BPN could overcome many of the barriers in current OAT models and aid scale-up of treatment coverage in Australia, including in rural and regional areas, and among emerging opioid-dependent groups (e.g. those dependent upon pharmaceutical opioids). An Australian randomised XR-BPN trial would add to the limited international evidence-base for the intervention and determine efficacy and suitability within the local opioid-dependent population. Independently collected data are therefore urgently needed on outcomes, acceptability and cost-effectiveness of XR-BPN in Australia.



The PREFER study aims to evaluate patient preferences for opioid agonist treatment (OAT) in Australia among people who regularly use opioids.

The study also seeks to also understand factors associated with preferences for different types of opioid agonist treatment.


Design and Method: 


The PREFER study will be a cross-sectional cohort study of 350-400 people who regularly use opioids.

Participants will be recruited from a range of services, including needle and syringe programs, drug and alcohol treatment services, other organisations providing support and services for people who use drugs, advocacy organisations representing people who use drugs, and pharmacies. Participants will also be recruited through snowballing (where eligible participants promote the study via their personal networks) and through word of mouth.

An email with a study flyer (including the details of the study and the contact information of the lead researcher) will be sent to services involved in studies that are ongoing through the investigator team. The study will be advertised at services using posters and flyers, but service staff will not be directly involved in recruitment. Service staff may refer participants to the study researchers that they believe are eligible for the study. Service staff will receive compensation of $10 for each eligible participant they refer to cover any costs incurred with time spent advertising the study. Study researchers will then contact eligible participants. Interested persons can also contact the study researchers directly to schedule an interview at their convenience.



Currently recruiting



It is anticipated that the findings of the PREFER study will contribute to research on patient preferences for opioid agonist treatment.


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