Treatment-seeking behaviour among people with opioid use disorder in the high-income countries: A systematic review and meta-analysis

Measuring the importance of different barriers to opioid agonist treatment using best-worst scaling in an Australian setting

OBJECTIVE

Opioid agonist treatment (OAT) is an effective treatment for opioid use disorder (OUD), however several client barriers to OAT are reported. Client importance of these barriers using economic preference elicitation measures have not been identified. This paper determines the most important OAT barriers using best-worst scaling (BWS) and compares the results of BWS to Likert scale.

METHODS

Cross-sectional self-completed survey with 191 opioid dependent clients who attended Australian needle and syringe sites. Participants were presented 15 Likert scale barriers and 15 BWS barrier scenarios. The BWS data was presented using count analysis, multinomial logit and mixed logit models. The ranking of barrier items was completed using three BWS methods and one Likert scale method, with share preference results (BWS) or mean scores (Likert) used to rank the 15 barriers.

RESULTS

The most important client barriers were 'enjoy using opioids', 'lack of support services' and 'hard to access'. The four ranking methods produced different barrier rankings for the most important barriers, but similar results for the least important barriers.

CONCLUSION

Policies around OAT as a harm reduction approach, increased support services and increased availability of OAT services would be beneficial in improving OAT uptake. Comparing BWS and Likert methods produced different highest ranked barriers, indicating the method used to identify preferences has significant implications on the type of intervention prioritised.

Estimated Clinical Outcomes and Cost-effectiveness Associated With Provision of Addiction Treatment in US Primary Care Clinics

Importance

US primary care practitioners (PCPs) are the largest clinical workforce, but few provide addiction care. Primary care is a practical place to expand addiction services, including buprenorphine and harm reduction kits, yet the clinical outcomes and health care sector costs are unknown.

Objective

To estimate the long-term clinical outcomes, costs, and cost-effectiveness of integrated buprenorphine and harm reduction kits in primary care for people who inject opioids.

Design, Setting, and Participants

In this modeling study, the Reducing Infections Related to Drug Use Cost-Effectiveness (REDUCE) microsimulation model, which tracks serious injection-related infections, overdose, hospitalization, and death, was used to examine the following treatment strategies: (1) PCP services with external referral to addiction care (status quo), (2) PCP services plus onsite buprenorphine prescribing with referral to offsite harm reduction kits (BUP), and (3) PCP services plus onsite buprenorphine prescribing and harm reduction kits (BUP plus HR). Model inputs were derived from clinical trials and observational cohorts, and costs were discounted annually at 3%. The cost-effectiveness was evaluated over a lifetime from the modified health care sector perspective, and sensitivity analyses were performed to address uncertainty. Model simulation began January 1, 2021, and ran for the entire lifetime of the cohort.

Main Outcomes and Measures

Life-years (LYs), hospitalizations, mortality from sequelae (overdose, severe skin and soft tissue infections, and endocarditis), costs, and incremental cost-effectiveness ratios (ICERs).

Results

The simulated cohort included 2.25 million people and reflected the age and gender of US persons who inject opioids. Status quo resulted in 6.56 discounted LYs at a discounted cost of $203 500 per person (95% credible interval, $203 000-$222 000). Each strategy extended discounted life expectancy: BUP by 0.16 years and BUP plus HR by 0.17 years. Compared with status quo, BUP plus HR reduced sequelae-related mortality by 33%. The mean discounted lifetime cost per person of BUP and BUP plus HR were more than that of the status quo strategy. The dominating strategy was BUP plus HR. Compared with status quo, BUP plus HR was cost-effective (ICER, $34 400 per LY). During a 5-year time horizon, BUP plus HR cost an individual PCP practice approximately $13 000.

Conclusions and Relevance

This modeling study of integrated addiction service in primary care found improved clinical outcomes and modestly increased costs. The integration of addiction service into primary care practices should be a health care system priority.