Objective: Use focus groups, a Delphi panel, and multiple iterations of cognitive pretesting to develop a patient-reported outcome (PRO) measure of function in Huntington’s disease (HD).

Background: FuRST 2.0 is a PRO measure of function designed to be sensitive to HD stage 2 and mild stage 3, as defined by the new HD Integrated Staging System (HD-ISS) (1).

Method: We followed standard assessment development methodology to create a PRO. In study 1 a Delphi panel analyzed data from focus groups of HD (n = 62) and companions (n=41) using framework analyses and a Content Validity Ratio (CVR) statistic to rank domains of interest and draft potential items. This was followed by four rounds of cognitive pretesting in which structured interviews were conducted with HD (studies 2-5) and companions (studies 2-3). Study 2 consisted of interviews with 40 HD and 35 companions while study 3 consisted of interviews with 39 HD and 11 companions. In study 4 a video conference group interview was conducted with 5 HD and in study 5 individual video conference interviews with 6 HD were conducted.  Qualitative analyses evaluated the respondents’ comprehension of the instructions, understanding of question and response options, and comfort with the material. Informal advice from a regulatory agency was received throughout the process.

Results: In study 1 the Delphi panel created 18 domains of interest and formed a 5-point Likert-type scale in a PRO format with 22 items. The analyses in study 2 resulted in a modified scale with 24 items, 4-point Likert-type response options, and a disclaimer.  In study 3 further modifications were made to the instructions, questions, and response options.  In study 4 response options were modified after obtaining participant consensus on specific points. Final fine tuning of wording was achieved using the individual interviews of study 5, culminating in the FuRST 2.0 official working document (OWD). Results will be presented in terms of the new HD-ISS (1).

Conclusion: When developing PRO measures, obtaining the patient voice through focus groups and cognitive pretesting is vital.  Cognitive pretesting requires multiple iterations resulting in an OWD.  The OWD of the FuRST 2.0 is available and will be evaluated in a large validation study.

References: (1) Tabrizi, Sarah J., et al. “Huntington’s Disease Integrated Staging System (HD-ISS): A Novel Evidence-Based Classification System For Staging.” medRxiv (2021).

« Back to 2022 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/functional-rating-scale-2-0-furst2-0-a-patient-reported-outcome-measure-for-huntingtons-disease-the-importance-of-the-patient-voice-in-scale-development/