Developing a core outcome set for Meniere’s disease trials, the COSMED study: results from two separate, two-round Delphi surveys on outcome domains and outcomes

Background Inconsistencies in outcome measures used in randomized controlled trials (RCTs) in Menière’s Disease (MD) make it challenging to compare trial results. A Core Outcome Set (COS) standardizes outcome measures across studies, improving comparability and enhancing data synthesis for stronger evidence in clinical trials. Objective To develop a consensus-based COS for MD trials by identifying the most clinically relevant outcome domains and outcomes, using a Delphi procedure. Methods Two two-round Delphi surveys were conducted among international experts, including ENT specialists, neurologists, audiologists, and clinical researchers, to identify outcome domains and outcomes for inclusion in the COS. Participants assessed the importance of MD-related outcome domains in the first Delphi survey, and outcomes in the second Delphi survey using a 9-point Likert scale, with predefined consensus thresholds determining inclusion. Results A total of 112 experts from 35 countries participated in this study, each completing at least one Delphi round. In the first Delphi, consensus was reached on inclusion of six out of twelve predefined outcome domains: body function and structures, hearing, dizziness, tinnitus, aural fullness, and quality of life. In the second Delphi, consensus was reached on the inclusion of the following additional outcomes: dizziness severity, number of vertigo attacks, duration of vertigo attack, hearing loss, pure tone average, tinnitus severity, aural fullness severity, quality of life related to dizziness, quality of life related to hearing, quality of life related to social activity or work, drop attacks and vestibular function. Conclusion This study represents a key phase of the COSMED-study through two structured, two-round Delphi procedures on outcome domains and outcomes to be considered in the COS for MD.