HDQLIFE: development and assessment of health-related quality of life in Huntington disease (HD).

PURPOSE: Huntington disease (HD) is a chronic, debilitating genetic disease that affects physical, emotional, cognitive, and social health. Existing patient-reported outcomes (PROs) of health-related quality of life (HRQOL) used in HD are neither comprehensive, nor do they adequately account for clinically meaningful changes in function. While new PROs examining HRQOL (i.e., Neuro-QoL-Quality of Life in Neurological Disorders and PROMIS-Patient-Reported Outcomes Measurement Information System) offer solutions to many of these shortcomings, they do not include HD-specific content, nor have they been validated in HD. HDQLIFE addresses this by validating 12 PROMIS/Neuro-QoL domains in individuals with HD and by using established PROMIS methodology to develop new, HD-specific content. METHODS: New item pools were developed using cognitive debriefing with individuals with HD, and expert, literacy, and translatability reviews. Existing item banks and new item pools were field tested in 536 individuals with prodromal, early-, or late-stage HD. RESULTS: Moderate to strong relationships between Neuro-QoL/PROMIS measures and generic self-report measures of HRQOL, and moderate relationships between Neuro-QoL/PROMIS and clinician-rated measures of similar constructs supported the validity of Neuro-QoL/PROMIS in individuals with HD. Exploratory and confirmatory factor analysis, item response theory, and differential item functioning analyses were utilized to develop new item banks for Chorea, Speech Difficulties, Swallowing Difficulties, and Concern with Death and Dying, with corresponding six-item short forms. A four-item short form was developed for Meaning and Purpose. CONCLUSIONS: HDQLIFE encompasses both validated Neuro-QoL/PROMIS measures, as well as five new scales in order to provide a comprehensive assessment of HRQOL in HD.

HDQLIFE: the development of two new computer adaptive tests for use in Huntington disease, Speech Difficulties, and Swallowing Difficulties.

PURPOSE: Huntington disease (HD) is an autosomal dominant neurodegenerative disease which results in several progressive symptoms, including bulbar dysfunction (i.e., speech and swallowing difficulties). Although difficulties in speech and swallowing in HD have a negative impact on health-related quality of life, no patient-reported outcome measure exists to capture these difficulties that are specific to HD. Thus, we developed a new patient-reported outcome measure for use in the Huntington Disease Health-Related Quality of Life (HDQLIFE) Measurement System that focused on the impact that difficulties with speech and swallowing have on HRQOL in HD. METHODS: Five hundred and seven individuals with prodromal and/or manifest HD completed 47 newly developed items examining speech and swallowing difficulties. Unidimensional item pools were identified using exploratory factor analysis and confirmatory factor analysis (EFA and CFA, respectively). Item response theory (IRT) was used to calibrate the final measures. RESULTS: EFA and CFA identified two separate unidimensional sets of items: Speech Difficulties (27 items) and Swallowing Difficulties (16 items). Items were calibrated separately for these two measures and resulted in item banks that can be administered as computer adaptive tests (CATs) and/or 6-item, static short forms. Reliability of both of these measures was supported through high correlations between the simulated CAT scores and the full item bank. CONCLUSIONS: CATs and 6-item calibrated short forms were developed for HDQLIFE Speech Difficulties and HDQLIFE Swallowing Difficulties. These measures both demonstrate excellent psychometric properties and may have clinical utility in other populations where speech and swallowing difficulties are prevalent.