Objectives. The objectives of this study were to elicit health utility scores for moderate Alzheimer's disease (AD) using members of the general public. Methods. Five-hundred Canadians were chosen randomly to participate in a telephone interview. The EQ-5D was administered to estimate the health utility score for respondents' current health status (i.e., no AD) and for a hypothetical moderate AD health state. Regression analyses were conducted to explain the perceived utility decrement associated with AD. Results. The mean age of the respondents was 51 years, 60% were female, and 42% knew someone with AD. Respondents' mean EQ-5D scores for their current health status and a hypothetical moderate AD were 0.873 (SD: 0.138) and 0.638 (SD: 0.194), respectively ( ). Age, gender, and education were significant factors explaining this decrement in utility. Conclusion. Members of the general public may serve as an alternative to patients and caregivers in the elicitation of health-related quality of life in AD. 1. Introduction Alzheimer’s disease (AD), the most common form of dementia, is the fifth leading cause of death in the United States (US) among persons aged 65 years or older [1]. Approximately 5.3 million Americans have AD, 5.1 million of whom are over the age of 65 years [2]. The financial burden of AD and other dementias is considerable, with an estimated annual total cost of $148 billion in the US in 2005 [3]. The annual cost per patient in the US was found to be three times higher for persons with AD and other dementias relative to persons without AD or other dementias (i.e., $33,007 relative to $10,603 in 2004) [3]. Other studies conducted in the US or elsewhere similarly concluded that AD costs were high and likely to rise over time due to the aging of the population [4–7]. Although several medications have been approved to treat AD (e.g., cholinesterase inhibitors, memantine), some jurisdictions (e.g., United Kingdom [8], Ontario, Canada [9]) limit reimbursement of these drugs (e.g., reimbursement in the United Kingdom is limited to persons with moderate AD only). The most prominent reasons for limiting reimbursement are grounded in the fact that the medications treat the symptoms of AD only (they are not a cure) [10] and cost between $2.90 and $6.80 per pill (US figures) [11]. In a cost-containment environment, economic evaluations are playing an increasingly important role in pricing and reimbursement decisions, [12], especially for relatively expensive medications that have modest efficacy. In AD, cognitive decline continues when persons with
References
[1]
M. Heron, D. L. Hoyert, S. L. Murphy, J. Xu, K. D. Kochanek, and B. Tejada-Vera, “Deaths: final data for 2006,” National Vital Statistics Reports, vol. 57, no. 14, pp. 1–134, 2009.
[2]
Alzheimer's Association, Early Onset Dementia: A National Challenge, a Future Crisis, Alzheimer's Association, Washington, DC, USA, 2006.
[3]
Alzheimer's Association, “2009 Alzheimer's disease facts and figures,” Alzheimers Dement, vol. 5, no. 3, pp. 234–270, 2009.
[4]
Alzheimer's Association, Saving Lives. Saving Money: Dividends for Americans Investing in Alzheimer Research. Report of the Lewin Group to the Alzheimer's Association, Alzheimer's Association, Washington, DC, USA, 2004.
[5]
B. S. Bloom, N. de Pouvourville, and W. L. Straus, “Cost of illness of Alzheimer's disease: how useful are current estimates?” Gerontologist, vol. 43, no. 2, pp. 158–164, 2003.
[6]
J. Lopez-Bastida, P. Serrano-Aguilar, L. Perestelo-Perez, and J. Oliva-Moreno, “Social-economic costs and quality of life of Alzheimer disease in the Canary Islands, Spain,” Neurology, vol. 67, no. 12, pp. 2186–2191, 2006.
[7]
Y. Zhao, T. C. Kuo, S. Weir, M. S. Kramer, and A. S. Ash, “Healthcare costs and utilization for medicare beneficiaries with Alzheimer's,” BMC Health Services Research, vol. 8, p. 108, 2008.
[8]
National Institute for Health and Clinical Excellence: Technology Appraisals TA19. 2001. [http://guidance.nice.org.uk/TA19].
[9]
Ontario Ministry of Health and Long-Term Care: e-Formulary. Ontario drug benefit formulary/comparative drug index: electronic version. Toronto: Queen's Printer for Ontario; 2007. [https://www.healthinfo.moh.gov.on.ca/formulary/index.jsp].
[10]
P. Raina, P. Santaguida, A. Ismaila et al., “Effectiveness of cholinesterase inhibitors and memantine for treating dementia: evidence review for a clinical practice guideline,” Annals of Internal Medicine, vol. 148, no. 5, pp. 379–397, 2008.
[11]
G. H. Suh, A. Wimo, S. Gauthier et al., “International price comparisons of Alzheimer's drugs: a way to close the affordability gap,” International Psychogeriatrics, vol. 21, no. 6, pp. 1116–1126, 2009.
[12]
T. Y. Tarn, “Pharmacoeconomic guidelines around the world,” ISPOR Connections, vol. 10, pp. 5–12, 2004.
[13]
R. G. Logsdon, L. E. Gibbons, S. M. McCurry, and L. Teri, “Assessing quality of life in older adults with cognitive impairment,” Psychosomatic Medicine, vol. 64, no. 3, pp. 510–519, 2002.
[14]
S. C. Smith, D. L. Lamping, S. Banerjee et al., “Development of a new measure of health-related quality of life for people with dementia: DEMQOL,” Psychological Medicine, vol. 37, no. 5, pp. 737–746, 2007.
[15]
A. J. Revell, G. I. Caskie, S. L. Willis, and K. W. Schaie, “Factor structure and invariance of the quality of life in alzheimer's disease (QoL-AD) scale,” Experimental Aging Research, vol. 35, no. 2, pp. 250–267, 2009.
[16]
A. Williams, “EuroQol—a new facility for the measurement of health-related quality of life,” Health Policy, vol. 16, no. 3, pp. 199–208, 1990.
[17]
G. W. Torrance, W. Furlong, D. Feeny, and M. Boyle, “Multi-attribute preference functions. Health utilities index,” PharmacoEconomics, vol. 7, no. 6, pp. 503–520, 1995.
[18]
J. Ankri, B. Beaufils, J. L. Novella et al., “Use of the EQ-5D among patients suffering from dementia,” Journal of Clinical Epidemiology, vol. 56, no. 11, pp. 1055–1063, 2003.
[19]
W. Coucill, S. Bryan, P. Bentham, A. Buckley, and A. Laight, “EQ-5D in patients with dementia: an investigation of inter-rater agreement,” Medical Care, vol. 39, no. 8, pp. 760–771, 2001.
[20]
L. J？nsson, N. Andreasen, L. Kilander et al., “Patient- and proxy-reported utility in Alzheimer disease using the EuroQoL,” Alzheimer Disease and Associated Disorders, vol. 20, no. 1, pp. 49–55, 2006.
[21]
J. H. Karlawish, A. Zbrozek, B. Kinosian, A. Gregory, A. Ferguson, and H. A. Glick, “Preference-based quality of life in patients with Alzheimer's disease,” Alzheimer's and Dementia, vol. 4, no. 3, pp. 193–202, 2008.
[22]
G. Naglie, G. Tomlinson, C. Tansey et al., “Utility-based quality of life measures in Alzheimer's disease,” Quality of Life Research, vol. 15, no. 4, pp. 631–643, 2006.
[23]
L. Thorgrimsen, A. Selwood, A. Spector et al., “Whose quality of life is it anyway? the validity and reliability of the quality of life-Alzheimer's disease (QoL-AD) scale,” Alzheimer Disease and Associated Disorders, vol. 17, no. 4, pp. 201–208, 2003.
[24]
J. H. Karlawish, A. Zbrozek, B. Kinosian et al., “Caregivers' assessments of preference-based quality of life in Alzheimer's disease,” Alzheimer's and Dementia, vol. 4, no. 3, pp. 203–211, 2008.
[25]
H. A. Kiyak, L. Teri, and S. Borson, “Physical and functional health assessment in normal aging and in Alzheimer's disease: self-reports vs family reports,” Gerontologist, vol. 34, no. 3, pp. 324–330, 1994.
[26]
R. E. Ready, B. R. Ott, and J. Grace, “Patient versus informant perspectives of quality of life in mild cognitive impairment and Alzheimer's disease,” International Journal of Geriatric Psychiatry, vol. 19, no. 3, pp. 256–265, 2004.
[27]
L. P. Sands, P. Ferreira, A. L. Stewart, M. Brod, and K. Yaffe, “What explains differences between dementia patients' and their caregivers' ratings of patients' quality of life?” American Journal of Geriatric Psychiatry, vol. 12, no. 3, pp. 272–280, 2004.
[28]
A. Vogel, E. L. Mortensen, S. G. Hasselbalch, B. B. Andersen, and G. Waldemar, “Patient versus informant reported quality of life in the earliest phases of Alzheimer's disease,” International Journal of Geriatric Psychiatry, vol. 21, no. 12, pp. 1132–1138, 2006.
[29]
M. F. Folstein, S. E. Folstein, and P. R. McHugh, “'Mini mental state'. A practical method for grading the cognitive state of patients for the clinician,” Journal of Psychiatric Research, vol. 12, no. 3, pp. 189–198, 1975.
[30]
M. Oremus, J. E. Tarride, N. Clayton, and P. Raina, “Support for a tax increase to provide unrestricted access to an Alzheimer's disease medication: a survey of the general public in Canada,” BMC Health Services Research, vol. 9, p. 246, 2009.
[31]
S. Dorofeev and P. Grant, Statistics for Real-Life Sample Surveys: Non-Simple-Random Samples and Weighted Data, Cambridge University Press, New York, NY, USA, 2006.
L. Dieckmann, S. H. Zarit, J. M. Zarit, and M. Gatz, “The Alzheimer's disease knowledge test,” The Gerontologist, vol. 28, no. 3, pp. 402–407, 1988.
[34]
L. X. Badia, S. N. Lara, and G. M. Roset, “[Quality of life, time commitment and burden perceived by the principal informal caregiver of Alzheimer's patients],” Atencion Primaria, vol. 34, no. 4, pp. 170–177, 2004.
[35]
B. Leung, N. Luo, L. So, and H. Quan, “Comparing three measures of health status (perceived health with Likert-type scale, EQ-5D, and number of chronic conditions) in Chinese and white Canadians,” Medical Care, vol. 45, no. 7, pp. 610–617, 2007.
[36]
Agency for Healthcare Research and Quality: Calculating the U.,S. population-based EQ-5D index score. Rockville, MD.: 2005. http://www.ahrq.gov/rice/EQ5Dscore.htm.
[37]
WISE & Healthy Aging, Alzheimer's Disease. Signs, Symptoms, and Stages of Alzheimer's Disease, WISE & Healthy Aging, Santa Monica, Calif, USA, 2009.
[38]
E. Pullenayegum, J. E. Tarride, F. Xie, R. Goeree, H. C. Gerstein, and D. O'Reilly, “Analysis of health utility data when some subjects attain the upper bound of 1: are tobit and clad models appropriate?” Value in Health, vol. 13, no. 4, pp. 487–494, 2010.
[39]
B. D. Carpenter, S. Balsis, P. G. Otilingam, P. K. Hanson, and M. Gatz, “The Alzheimer's disease knowledge scale: development and psychometric properties,” Gerontologist, vol. 49, no. 2, pp. 236–247, 2009.
