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An International Multi-Stakeholder Delphi Survey Study on the Design of Disease Modifying Parkinson's Disease Trials

Lookup NU author(s): Professor Camille CarrollORCiD



This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).


© 2023 - The authors. Published by IOS Press. Background: Design of disease modification (DM) trials for Parkinson's disease (PD) is challenging. Successful delivery requires a shared understanding of priorities and practicalities. Objective: To seek stakeholder consensus on phase 3 trials' overall goals and structure, inclusion criteria, outcome measures, and trial delivery and understand where perspectives differ. Methods: An international expert panel comprising people with Parkinson's (PwP), care partners (CP), clinical scientists, representatives from industry, funders and regulators participated in a survey-based Delphi study. Survey items were informed by a scoping review of DM trials and PwP input. Respondents scored item agreement over 3 rounds. Scores and reasoning were summarized by participant group each round until consensus, defined as≥70% of at least 3 participant groups falling within the same 3-point region of a 9-point Likert scale. Results: 92/121 individuals from 13 countries (46/69 PwP, 13/18 CP, 20/20 clinical scientists, representatives from 8/8 companies, 4/5 funders, and 1/1 regulator) completed the study. Consensus was reached on 14/31 survey items: 5/8 overall goals and structure, 1/8 Eligibility criteria, 7/13 outcome measures, and 1/2 trial delivery items. Extent of stakeholder endorsement for 428 reasons for scores was collated across items. Conclusions: This is the first systematic multi-stakeholder consultation generating a unique repository of perspectives on pivotal aspects of DM trial design including those of PwP and CP. The panel endorsed outcomes that holistically measure PD and the importance of inclusive trials with hybrid delivery models. Areas of disagreement will inform mitigating strategies of researchers to ensure successful delivery of future trials.

Publication metadata

Author(s): Zeissler M-L, McFarthing K, Raphael KG, Rafaloff G, Windle R, Carroll CB

Publication type: Article

Publication status: Published

Journal: Journal of Parkinson's Disease

Year: 2023

Volume: 13

Issue: 8

Pages: 1343-1356

Print publication date: 19/12/2023

Online publication date: 18/11/2023

Acceptance date: 23/10/2023

Date deposited: 30/01/2024

ISSN (print): 1877-7171

ISSN (electronic): 1877-718X

Publisher: IOS Press BV


DOI: 10.3233/JPD-230109

PubMed id: 38007672


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Funder referenceFunder name
Cure Parkinson's