Measuring the preferences of injectable opioid agonist treatment (iOAT) clients: Development of a person-centered scale (best-worst scaling).

BACKGROUND:Injectable opioid agonist treatment (iOAT) is effective for opioid use disorder (OUD), yet little is known about client preferences for accessing iOAT (e.g., with diacetylmorphine, hydromorphone, buprenorphine, fentanyl, etc.). Best-worst scaling (BWS) is a preference elicitation method from health economics that has never been applied to addiction care broadly, or iOAT specifically. We describe the stages of developing a BWS scale that assesses iOAT clients' treatment delivery preferences to inform program planning and maximize healthcare efficiency. METHODS:We underwent several steps to reveal the relevant attributes/levels and design the scale structure. An initial list of potential attributes and levels was established from a literature review and prior qualitative data. Then, we conducted semi-structured interviews and focus groups with clients (n=21) on their iOAT preferences to confirm the attributes and prioritize/include new ones. Next, we conducted semi-structured interviews and focus groups with iOAT experts and stakeholders to receive their input on the draft list of attributes and levels. A BWS profile case design was piloted with iOAT clients (n=18) from different sites during a think aloud interview. After several rounds of revisions, the final version was tested by iOAT clients (n=2) before the scale was launched. RESULTS:We developed a person-centered scale that assesses current and former iOAT clients' most and least wanted aspects of iOAT delivery. The final version yielded 7 unique attributes: choice of medication, choice of dose, convenience, location & space, scheduling & routines, staff & training, and types of services offered. CONCLUSION:This scale can help expand iOAT programs in a way that is person-centered, rapid, and affordable. The methodology is a guide for other regions with similar populations who aim to develop strong quantitative methodologies that prioritize client collaboration.