Understanding the relative importance of preserving functional abilities in Alzheimer’s disease in the United States and Germany A. Brett Hauber • Ateesha F. Mohamed • F. Reed Johnson • Michael Cook • H. Michael Arrighi • Jing Zhang • Michael Grundman Accepted: 30 December 2013 / Published online: 22 January 2014 Ó Springer Science+Business Media Dordrecht 2014 Abstract Purpose To estimate the relative importance that Alz- heimer’s disease (AD) caregivers in the United States and Germany place on preserving patients’ ability to perform activities of daily living. Methods US and German residents providing care for a person with AD completed an online preference survey. Each respondent completed five best–worst scaling ques- tions. Each question related to five of 10 activities from the Disability Assessment for Dementia scale. Preference weights, indicating the relative importance of preserving the ability to perform these 10 activities for 36 months, were estimated using maximum-difference scaling. A separate model was estimated for each country. Results Four hundred and three US and 400 German caregivers completed the survey. In both countries, pre- serving a patients’ ability to use the toilet without accidents was the most important activity and handling money was the least important activity. There were few differences between US and German caregivers in the relative impor- tance across activities. Conclusions Caregivers generally placed greater impor- tance on preserving basic activities of daily living than on preserving instrumental activities of daily living. Understanding differences in the relative importance of functional items in the DAD may contribute to a better understanding of the benefits of different AD treatment and support measures. Keywords Alzheimer’s disease Á Conjoint analysis Á Best–worst scaling Á Disability Assessment for Dementia Á Caregivers Á Preference Introduction Alzheimer’s disease (AD) is a form of dementia charac- terized by progressive deterioration in memory, cognition, and functional ability. The number of persons with AD in 2012 in the United States was estimated to be between 3.3 million [1] and 5.5 million [2]. The projected number of people with dementia in Europe was estimated at 9.95 million in 2010 [3]. In 2006, the estimated number of people with dementia in Germany was 1.4 million [4]. In the early stages of AD, patients may no longer be able to prepare meals or use the telephone; in the later stages, patients may not be able to wash, dress, or use the toilet without the aid of a caregiver [5]. As patients lose the ability to perform activities of daily living, they rely increasingly on assistance from caregivers to perform these functions. Lower functional capability has been shown to increase the burden of AD on caregivers [6]. Although patients may lose the ability to perform different functions at different times during the course of the disease, gener- ally losing the ability to perform instrumental activities of daily living earlier in the course of the disease and basic activities of daily living later in the course of the disease, the effects on the caregiver of a patient’s loss of different individual functional abilities remain unknown. A. B. Hauber (&) Á A. F. Mohamed Á F. R. Johnson Á J. Zhang RTI Health Solutions, 200 Park Offices Drive, Research Triangle Park, NC 27709-2194, USA e-mail: abhauber@rti.org M. Cook Pfizer, Inc., 500 Arcola Rd, Collegeville, PA 19426, USA H. M. Arrighi Á M. Grundman Janssen Alzheimer Immunotherapy Research & Development, 700 Gateway Blvd., South San Francisco, CA 94080, USA 123 Qual Life Res (2014) 23:1813–1821 DOI 10.1007/s11136-013-0620-5