Prospective Preference Assessment of Potential Participants in the Perioperative Rectal Methadone in Spine Surgery (PROMISE) Trial.

Background/Aims: Perioperative pain management in spine surgery is challenging, with many patients suffering from chronic pain. The favorable pharmacokinetic-dynamic profile of methadone may offer a novel approach to perioperative analgesia; however, stigma around methadone and rectal administration may bias patient enrollment. Before initiating a trial comparing rectal methadone to placebo, we conducted a prospective preference assessment (PPA) to identify barriers and motivators for participation and characterize differences between willing and unwilling participants to refine the trial protocol. Methods: Adult patients undergoing elective spinal surgery were recruited from St. Michael's Hospital's preoperative clinic from July to August 2024. Participants completed a PPA, including a trial vignette, assessment of understanding, open-ended questions exploring attitudes toward the trial, and a questionnaire. Data were analyzed with thematic analysis, t-test, and Fisher's exact test. Results: Thirty participants were enrolled and categorized based on a 6-point Likert scale into "willing" to participate (Likert 4-6, 83.3%, CI 0.69-0.98) and "not willing" (Likert 1-3, 16.7%, CI 0.0-0.49). Pain as a major concern was significantly associated with willingness to participate, with 88% of willing participants reporting it as a concern compared to 40% of non-willing participants (p = .04). Common motivators included optimizing pain management (57%) and perceived benefits of rectal methadone (30%). Common concerns were methadone side effects (13%) and dependency fears (13%). Conclusion: We identified a strong willingness (83.3%, CI 0.69-0.98) among spine surgery patients to participate in our trial. Protocol adjustments will focus on patient education regarding methadone's safety profile, clarifying measures to minimize dependency risks, and ensuring physiologic monitoring.