title: Measuring agreement between patient and proxy responses to multidimensional health-related quality-of-life measures in clinical trials. An application of psychometric profile analysis.
abstract: When patients cannot provide responses to health-related quality-of-life (HRQOL) measures in clinical trials, family or friends may be asked to respond. We present a simple, comprehensive method for assessing agreement between patients with head injury and their proxy responders. In contrast to more traditional approaches, this method defines agreement separately for each patient-proxy pair, and compares HRQOL profiles along three dimensions-level, or the average of the ratings; scatter, or the variability in the ratings; and shape, or the ranks of the ratings. We demonstrate this method in the context of a clinical trial of a treatment for traumatic head injury and compare the results to those obtained using traditional analyses. Options for incorporating proxy responses into clinical trial analyses are discussed.
authors.affiliation: Center for Clinical and Genetic Economics, Duke Clinical Research Institute, Duke University Medical Center, Durham, NC 17969-27715, USA. kevin.weinfurt@duke.edu
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Weinfurt
authors.forename: Sara M
authors.initials: SM
authors.lastname: Trucco
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Willke
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Schulman
mesh_terms: D000203:Activities of Daily Living; D006259:Craniocerebral Trauma; D003657:Decision Making; D006304:Health Status; D006801:Humans; D017063:Outcome Assessment, Health Care / Q000379:methods*; D019727:Proxy; D011594:Psychometrics / Q000379:methods*; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D012107:Research Design