Developing a core outcome set for dysphagia interventions in Parkinson's disease: an international Delphi consensus study.

Objectives: To develop a core outcome set (COS) for oropharyngeal dysphagia (swallowing disorder) interventions in Parkinson's disease by agreeing core outcomes and definitions, outcome measurement instruments (OMIs) and time points of measurement for these core outcomes.

Design: International online Delphi survey and consensus meetings.

Participants: Individuals living with oropharyngeal dysphagia and Parkinson's disease, family members and caregivers, healthcare professionals and researchers in the field of oropharyngeal dysphagia and Parkinson's disease.

Methods: A long list of outcomes was generated previously through scoping reviews, online surveys and focus groups with key stakeholders. Building on this, an international three-round online Delphi survey was conducted where participants rated the importance of outcomes. In subsequent online consensus meetings, core outcomes, their definitions, OMIs and time points of measurement were agreed on.

Results: 90 participants from 21 countries completed all three rounds of the Delphi survey. Of these, 35 participated in a consensus meeting. Six outcomes were agreed as the core outcomes: 'penetration/aspiration', 'aspiration pneumonia', 'choking', 'oropharyngeal dysphagia severity', 'swallowing related quality of life' and 'post swallow pharyngeal residue'.

Conclusions: The use of a COS in future oropharyngeal dysphagia intervention studies in Parkinson's disease will facilitate comparative effectiveness research and ensure that outcomes are relevant to all key stakeholders. This should help improve the evidence base for oropharyngeal dysphagia interventions in Parkinson's disease.

Registration: The study was registered prospectively with the Core Outcome Measures in Effectiveness Trials Database on 24 September 2021 (www.comet-initiative.org, registration number: 1942).