Health utilities in Alzheimer's disease - A cross-sectional study of patients and caregivers

OBJECTIVES. Although the broad impacts of Alzheimer's disease (AD) are incr easingly recognized, little work has focused on the overall health-related quality of life experienced by Alzheimer's disease patients and their careg ivers. The study had two main objectives: (1) to test the feasibility of me asuring health utilities in Alzheimer's disease with a generic preference-w eighted instrument using proxy respondents and (2) to assess the utility sc ores of Alzheimer's disease patients (and their caregivers) in different di sease stages and care setting. METHODS. A cross-sectional study of 679 Alzheimer's disease patient/caregiv er pairs was conducted at 13 sites in the United States: four academic medi cal centers, four managed care plans, two assisted living facilities, and t hree nursing homes. The Health Utilities Index Mark II (HUI:2) questionnair e was administered to caregivers of patients who responded both as proxies for patients and for themselves. Responses to the questionnaire were conver ted into a global utility score, between 0 and 1, using the HUI:2 multi-att ribute utility function. RESULTS. Global utility scores varied considerably across patients' Alzheim er's disease stage: for the six stages assessed (questionable, mild, modera te, severe, profound, and terminal), mean utility scores were 0.73, 0.69, 0 .53, 0.38, 0.27, and 0.14, respectively. In multiple regression analyses, A lzheimer's disease stage was a negative and significant predictor of utilit y scores for patients; setting did not exert an independent effect. Utility scores for the caregivers were insensitive to patients' Alzheimer's diseas e stage and setting. CONCLUSIONS. Patients' Alzheimer's disease stage had a substantial influenc e on health utilities, as measured by the HUI:2. More research is needed to assess the validity of using proxy respondents.