The Huntington’s Disease Health Index: Initial Evaluation of a Disease-Specific Patient Reported Outcome Measure

Article type: Research Article

Authors: Brumfield, Olivia S.^a | Zizzi, Christine E.^{a; c} | Dilek, Nuran^b | Alexandrou, Danae G.^a | Glidden, Alistair M.^a | Rosero, Spencer^a | Weinstein, Jennifer^a | Seabury, Jamison^a | Kaat, Aaron^e | McDermott, Michael P.^{b; d} | Dorsey, E. Ray^{a; b} | Heatwole, Chad R.^{a; b; *}

Affiliations: [a] Center for Health + Technology, University of Rochester, Rochester, NY, USA | [b] Department of Neurology, University of Rochester, Rochester, NY, USA | [c] School of Public and International Affairs, Princeton University, Princeton, NJ, USA | [d] Department of Biostatistics and Computational Biology, University of Rochester, Rochester, NY, USA | [e] Department of Medical Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA

Correspondence: [*] Correspondence to: Chad R. Heatwole, MD, MS-CI, Center for Health + Technology, Saunders Research Building, 265 Crittenden Blvd, CU 420694, Rochester, NY 14642, USA. E-mail: [email protected].

Abstract: Background:When developed properly, disease-specific patient reported outcome measures have the potential to measure relevant changes in how a patient feels and functions in the context of a therapeutic trial. The Huntington’s Disease Health Index (HD-HI) is a multifaceted disease-specific patient reported outcome measure (PROM) designed specifically to satisfy previously published FDA guidance for developing PROMs for product development and labeling claims. Objective:In preparation for clinical trials, we examine the validity, reliability, clinical relevance, and patient understanding of the Huntington’s Disease Health Index (HD-HI). Methods:We partnered with 389 people with Huntington’s disease (HD) and caregivers to identify the most relevant questions for the HD-HI. We subsequently utilized two rounds of factor analysis, cognitive interviews with fifteen individuals with HD, and test-retest reliability assessments with 25 individuals with HD to refine, evaluate, and optimize the HD-HI. Lastly, we determined the capability of the HD-HI to differentiate between groups of HD participants with high versus low total functional capacity score, prodromal versus manifest HD, and normal ambulation versus mobility impairment. Results:HD participants identified 13 relevant and unique symptomatic domains to be included as subscales in the HD-HI. All HD-HI subscales had a high level of internal consistency and reliability and were found by participants to have acceptable content, relevance, and usability. The total HD-HI score and each subscale score statistically differentiated between groups of HD participants with high versus low disease burden. Conclusion:Initial evaluation of the HD-HI supports its validity and reliability as a PROM for assessing how individuals with HD feel and function.

Keywords: Huntington’s disease, patient reported outcome measure, therapeutic trial, quality of life, neurodegenerative disorder

DOI: 10.3233/JHD-210506

Journal: Journal of Huntington's Disease, vol. 11, no. 2, pp. 217-226, 2022