Towards a consensus approach to opioid substitution treatment outcomes and how they are monitored

Background: Different views exist on what opioid substitution treatment (OST – mainly methadone and buprenorphine) aims to achieve. At one extreme there is an expectation that OST should cure opioid dependence and thus a focus on “recovery” and reaching abstinence from illicit drug use with often shorter durations of OST. At the other end is the view (backed by research evidence) that OST is far more effective in preventing harms such as overdose (death) and infectious diseases (HIV, hepatitis) and achieving improvements or stabilization in social functioning and health. This view accepts long-term or indefinite OST duration (as in other chronic diseases treatments such as diabetes) with full abstinence achieved by a small minority, often only after a very long time. Similarly, there is a lack of consensus in OST outcome evaluation or monitoring (Wiessing et al. 2018). In Europe (the EU), although some countries have developed OST outcome monitoring, this is not the case in most countries. Also, where monitoring is in place, indicators and domains differ between countries (based on information from 7 European countries (6 from the EU) where outcome monitoring was reported, out of 16 countries participating in a 2018 EMCDDA/Treatment Demand Indicator (TDI) workshop).

Aims: To initiate a consensus process towards a common approach (guidance) for OST outcome monitoring, by agreeing indicators to evaluate quality and impact on individual and public health outcomes, facilitating cross-country and –service comparisons of OST effectiveness, initially among 30 EMCDDA-contributing countries. In the workshop this EMCDDA project will be presented and discussed with the audience to gain a better understanding of the barriers and facilitators of a common approach to OST outcome monitoring (including consensus domains, indicators and methods). It will be attempted to invite representatives from those EU countries with OST outcome monitoring in place to discuss their agreement with the consensus process.

Methods: Systematic review of longitudinal observational studies on OST outcome evaluation (Wiessing et al. 2018). Country expert workshop during the annual TDI meeting in 2018 where experts from 16 countries in 3 working groups prioritized a list of indicators with regard to their relevance and feasibility to measure public health impact of OST. Expert meeting in January 2019 with 18 participants (clinical, research, civil society, EMCDDA) to further prioritize outcome domains and indicators and to plan a Delphi approach to involve a wider group of stakeholders (e.g. people who use drugs, nurses, outreach workers etc.).

Results: The systematic review of 27 longitudinal observational studies on OST outcomes found large variation in domains and indicators used to assess successful treatment (Wiessing et al. 2018). Few studies used outcome indicators that assessed the main public health impacts /disease burden of opioid use (i.e. (overdose) death and HIV/hepatitis – World Drug Report 2017) suggesting a lack of (public) health relevance. Out of the 27 studies reviewed, only 2 studies included HIV or hepatitis C virus status and only 7 included injection among the outcomes reported; needle sharing was reported by 5 studies, sexual risk behaviour by 4 studies and overdose by 5 (Wiessing et al. 2018). Presented with these findings, the country representatives in the 2018 EMCDDA/TDI workshop did prioritize public health outcomes ((overdose) mortality and infectious diseases (HIV, HCV)) with the 3 groups being in agreement. At the 2019 expert meeting domains and indicators were further detailed. Delphi consensus process and outcomes will be presented as far as available (this will be work in progress). Workshop participants (audience) will be asked to answer questions on the feasibility of outcomes monitoring and are encouraged to discuss their national or local/regional experience in evaluating OST outcomes and to comment on the EMCDDA project outcomes so far. Country representatives of EU countries with monitoring in place will be encouraged to attend to discuss the compatibility of their national system with the Delphi consensus proposals.