F10 Development of assessments for later stage huntington’s disease: HD structured interview of function and HD clinical status questionnaire

Background There is a need for validated assessments for patients with later-stage HD. The LSA study aims to provide preliminary clinimetric properties for two such measures: the HD Structured Interview of Function (HD-SIF) and HD Clinical Status Questionnaire (HDCSQ). Both assessments are administered to a Companion Participant either in-person or remotely, and the properties of these tests will be evaluated using the methods of Classical Test Theory (CTT) and Item Response Theory (IRT). Objectives To obtain estimates for the clinimetric properties of the HD-SIF and HDCSQ. Methods Up to 170 dyads of Manifest HD Gene Expansion Carrier (mHDGEC) Participants and their Companion Participants are planned to be enrolled in this study from approximately 20 English-speaking study sites. The study includes two sequential parts. In Part 1, we will use the methods of CTT to evaluate the HD-SIF, a structured interview designed to gather information for making ratings on the UHDRSTM ‘99 functional scales (TFC, FAS and IS). In Part 2, we will use the methods of CTT and IRT to assess the clinimetric properties of the HDCSQ, a questionnaire designed specifically to capture information on disease milestones that occur during the later stages of HD, and the HD-SIF. In both parts, Companion Participants will complete a Companion Information Form, a short questionnaire asking about the Companion Participant’s perceptions and experiences as a caregiver/companion to the mHDGEC Participant. Status and Outlook A robust suite of training materials have been developed to train and certify HD-SIF and HDCSQ raters. This study is entering into the final phase of start-up with recruitment scheduled to run from 3Q2021 until 2023. Preliminary results from Part 1 will be available during 2022 and a full report will be available later that year. Upon establishing the clinimetric properties of the scales, these assessments may be used for planning studies or incorporated into observational and interventional studies of HD. Including a more advanced patient population will empower them to participate and will promote their valued contribution to research.