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Dementia-specific quality of life instruments: a conceptual analysis

Published online by Cambridge University Press:  22 March 2016

P. Missotten ,
G. Dupuis  and
S. Adam
P. Missotten*
Affiliation:
Psychology of Aging Unit, University of Liege (B63c), Liege, Belgium
G. Dupuis
Affiliation:
Department of Psychology, Université du Québec à Montréal (UQAM), Montreal, Canada
S. Adam
Affiliation:
Psychology of Aging Unit, University of Liege (B63c), Liege, Belgium
*
Correspondence should be addressed to: Missotten Pierre, Phd Psychology of Aging Unit, Department of Psychology, University of Liège (ULg) Traverse des Architectes (B63c), 4000 LIEGE, Belgium, BE. Phone: +32 4 366.20.58; Secretary: +32 4 366.20.81; Fax: +32 4 366.34.01. Email: [email protected].
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Abstract

Background:

Over the past 20 years, many researchers have worked in developing various methods for measuring quality of life (QoL) of people with dementia. The aim of this review is to develop the conceptual frameworks of the dementia-specific QoL instruments, to identify their evolution over time and to provide elements of reflection on the QoL concept in dementia and its evaluation.

Methods:

An electronic search was conducted on PsycINFO and MEDLINE databases, from January 1985 to June 2015 using a combination of key words that include QoL, dementia, and review.

Results:

The analysis of the conceptual frameworks of the 18 selected dementia-specific QoL tools shows a great diversity in: (1) the QoL definitions (e.g. health-related QoL definitions, QoL definitions based on Lawton's work, or similar to this latter); (2) the theoretical QoL models (e.g. Lawton’ work and modified Lawton, adaptation, personhood); (3) the domains and dimensions; (4) the way to construct the instrument (e.g. development based on literature, opinion of the experts), and (5) the items’ formulation (e.g. use of criterion of intensity or frequency).

Conclusions:

There are different conceptual frameworks in the dementia-specific QoL measures with improvements over time (e.g. inclusion of interesting concepts such as adaptation, taking into account the views of patients themselves). Each of the conceptual parameters (definitions, models, domains, and dimensions) is discussed to identify the scales that are conceptually the strongest. Through their review, recommendations for future instrument refinement and development are discussed and a new QoL definition is proposed.

Keywords

Alzheimer's diseasedementiaquality of life (QoL)scales
Type
Review Article
Information
International Psychogeriatrics , Volume 28 , Issue 8 , August 2016 , pp. 1245 - 1262
Copyright
Copyright © International Psychogeriatric Association 2016 

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References

Albert, S. M. et al. (1996). Quality of life in patients with Alzheimer's disease as reported by patient proxies. Journal of the American Geriatrics Society, 44, 1342–1347. doi: 10.1111/j.1532-5415.1996.tb01405.x.Google Scholar
Albert, S. M. et al. (2001). Longitudinal study of quality of life in people with advanced Alzheimer's disease. The American Journal of Geriatric Psychiatry, 9, 160–168. doi: 10.1097/00019442-200105000-00008.CrossRefGoogle ScholarPubMed
Arons, A. M., Krabbe, P. F., Schölzel-Dorenbos, C. J., van der Wilt, G. J. and Rikkert, M. G. (2013). Quality of life in dementia: a study on proxy bias. BMC Medical Research Methodology, 13, 110. doi: 10.1186/1471-2288-13-110.Google Scholar
Arons, A. M., Krabbe, P. F., Schölzel-Dorenbos, C. J., van der Wilt, G. J. and Rikkert, M. G. (2012). Thurstone scaling revealed systematic health-state valuation differences between patients with dementia and proxies. Journal of Clinical Epidemiology, 65, 897–905. doi: 10.1016/j.jclinepi.2012.01.018.CrossRefGoogle ScholarPubMed
Ballard, C. G. et al. (2004). A 3-month, randomized, placebo-controlled, neuroleptic discontinuation study in 100 people with dementia: the neuropsychiatric inventory median cutoff is a predictor of clinical outcome. Journal of Clinical Psychiatry, 65, 114–119.Google Scholar
Ballard, C. et al. (2002). Can psychiatric liaison reduce neuroleptic use and reduce health service utilization for dementia patients residing in care facilities?. International Journal of Geriatric Psychiatry, 17, 140–145. doi: 10.1002/gps.543.CrossRefGoogle ScholarPubMed
Baltes, P. B. and Baltes, M. M. (1990). Psychological perspectives on successful aging: The model of selective optimization with compensation. In Baltes, P. B. and Baltes, M. M. (eds.), Successful Aging: Perspectives from the Behavioral Sciences (pp. 1–34). New York: Cambridge University Press.Google Scholar
Banerjee, S. et al. (2009). What do we know about quality of life in dementia? A review of the emerging evidence on the predictive and explanatory value of disease specific measures of health related quality of life in people with dementia. International Journal of Geriatric Psychiatry, 24, 15–24. doi: 10.1002/gps.2090.Google Scholar
Black, B. S. et al. (2012). Quality of life of community-residing persons with dementia based on self-rated and caregiver-rated measures. Quality of Life Research, 21, 1379–1389. doi: 10.1007/s11136-011-0044-z.Google Scholar
Bowling, A. et al. (2015). Quality of life in dementia: a systematically conducted narrative review of dementia-specific measurement scales. Aging & Mental Health, 19, 13–31. doi: 10.1080/13607863.2014.915923.Google Scholar
Bredin, K., Kitwood, T. and Wattis, J. (1995). Decline in quality of life for patients with severe dementia following a ward merger. International Journal of Geriatric Psychiatry, 10, 967–973. doi: 10.1002/gps.930101109.Google Scholar
Brod, M., Stewart, A. L., Sands, L. and Walton, P. (1999). Conceptualization and measurement of quality of life in dementia: the dementia quality of life instrument (DQoL). The Gerontologist, 39, 25–35. doi: 10.1093/geront/39.1.25.Google Scholar
Brooker, D., Foster, N., Banner, A., Payne, M. and Jackson, L. (1998). The efficacy of dementia care mapping as an audit tool: report of a 3-year british NHS evaluation. Aging & Mental Health, 2, 60–70. doi: 10.1080/13607869856957.CrossRefGoogle Scholar
Brooks, R. (1996). EuroQol: the current state of play. Health Policy, 37, 53–72. doi: 10.1016/0168-8510(96)00822-6.Google Scholar
Bullinger, M., Anderson, R., Cella, D. and Aaronson, N. (1993). Developing and evaluating cross-cultural instruments from minimum requirements to optimal models. Quality of Life Research, 2, 451–459. doi: 10.1007/BF00422219.Google Scholar
Burgener, S. and Twigg, P. (2002). Relationships among caregiver factors and quality of life in care recipients with irreversible dementia. Alzheimer Disease & Associated Disorders, 16, 88–102. doi: 10.1097/00002093-200204000-00006.CrossRefGoogle ScholarPubMed
Byrne-Davis, L. M., Bennett, P. D. and Wilcock, G. K. (2006). How are quality of life ratings made? Toward a model of quality of life in people with dementia. Quality of Life Research, 15, 855–865. doi: 10.1007/s11136-005-5416-9.CrossRefGoogle Scholar
Carstensen, L. L. (1995). Evidence for a life-span theory of socioemotional selectivity. Current Directions in Psychological Science, 4, 151–156. doi: 10.1111/1467-8721.ep11512261.Google Scholar
Chiu, Y. C., Chiu, Y. F., Hsu, W. C., Lee, S. H., Chen, S. T. and Kao, H. Y. (2010). Developing a Chinese quality of life in dementia instrument for patients with early-to-moderate dementia: an exploratory test of validity. Journal of Clinical Nursing, 19, 2174–2184. doi: 10.1111/j.1365-2702.2010.03254.x.CrossRefGoogle ScholarPubMed
Clare, L. (2003). Managing threats to self: awareness in early stage Alzheimer's disease. Social Science & Medicine, 57, 1017–1029. doi: 10.1016/S0277-9536(02)00476-8.CrossRefGoogle ScholarPubMed
Clare, L., Goater, T. and Woods, B. (2006). Illness representations in early-stage dementia: a preliminary investigation. International Journal of Geriatric Psychiatry, 21, 761–767. doi: 10.1002/gps.1558.Google Scholar
Crespo, M., Hornillos, C. and Gomez, M. M. (2013). Assessing quality of life of nursing home residents with dementia: feasibility and limitations in patients with severe cognitive impairment. International Psychogeriatrics, 25, 1687–1695. doi: 10.1017/S1041610213000823.CrossRefGoogle ScholarPubMed
Davis, E. et al. (2006). Paediatric quality of life instruments: a review of the impact of the conceptual framework on outcomes. Developmental Medicine & Child Neurology, 48, 311–318. doi: 10.1017/S0012162206000673.Google Scholar
de Boer, M. E., Hertogh, C. M., Droes, R. M., Riphagen, II, Jonker, C. and Eefsting, J. A. (2007). Suffering from dementia – the patient's perspective: a review of the literature. International Psychogeriatrics, 19, 1021–1039. doi: 10.1017/S1041610207005765.Google Scholar
De Lepeleire, J. et al. (2010). Réflexions critiques à propos de l'euthanasie de personnes atteintes de demence. [Critical reflections concerning euthanasia for persons with dementia]. Revue Medicale de Liege, 65, 453–458.Google Scholar
Demers, L., Oremus, M., Perrault, A., Champoux, N. and Wolfson, C. (2000). Review of outcome measurement instruments in Alzheimer's disease drug trials: psychometric properties of functional and quality of life scales. Journal of Geriatric Psychiatry and Neurology, 13, 170–180. doi: 10.1177/089198870001300402.Google Scholar
Dröes, R. M. (1991). Beweging: over Psychosociale Hulpverlening aan Demente Ouderen. Utrecht: De Tijdstroom.Google Scholar
Dupuis, G., Perrault, J., Lambany, M. C., Kennedy, E. and David, P. (1989). A new tool to assess quality of life: the quality of life systemic inventory. Quality of Life and Cardiovascular Care, 5, 36–45.Google Scholar
Dupuis, G., Taillefer, M. C., Etienne, A. M., Fontaine, O., Boivin, S. and Von Turk, A. (2000). Measurement of quality of life in cardiac rehabilitation. In Jobin, J., Maltais, F., LeBlanc, P., Simard, C. and Kinetics, H. (eds.), Advances in Cardiopulmonary Rehabilitation (pp. 247–273). Champaign, IL: Human Kinetics.Google Scholar
Edelman, P., Fulton, B. R., Kuhn, D., Gallager, M. and Dougherty, J. (2007). Assessing quality of life across the dementia continuum. two new observational tools for researchers and practitioners. Alzheimer's Care Today, 8, 332–343. doi: 10.1097/01.ALCAT.0000297154.97526.bd.Google Scholar
Edvardsson, D., Fetherstonhaugh, D. and Nay, R. (2010). Promoting a continuation of self and normality: person-centred care as described by people with dementia, their family members and aged care staff. Journal of Clinical Nursing, 19, 2611–2618. doi: 10.1111/j.1365-2702.2009.03143.x.CrossRefGoogle Scholar
Ettema, T. P., Droes, R. M., de Lange, J., Ooms, M. E., Mellenbergh, G. J. and Ribbe, M. W. (2005a). The concept of quality of life in dementia in the different stages of the disease. International Psychogeriatrics, 17, 353–370. doi: 10.1017/S1041610205002073.CrossRefGoogle ScholarPubMed
Ettema, T. P., Droes, R.-M., de Lange, J., Mellenbergh, G. J. and Ribbe, M. W. (2005b). A review of quality of life instruments used in dementia. Quality of Life Research, 14, 675–686. doi: 10.1007/s11136-004-1258-0.CrossRefGoogle ScholarPubMed
Ettema, T. P., Droes, R.-M., de Lange, J., Mellenbergh, G. J. and Ribbe, M. W. (2007a). QUALIDEM: development and evaluation of a dementia specific quality of life instrument - validation. International Journal of Geriatric Psychiatry, 22, 424–430. DOI: 10.1002/gps.1692.Google Scholar
Ettema, T. P., Droes, R.-M., de Lange, J., Mellenbergh, G. J. and Ribbe, M. W. (2007b). QUALIDEM: development and evaluation of a dementia specific quality of life instrument. Scalability, reliability and internal structure. International Journal of Geriatric Psychiatry, 22, 549–556. doi: 10.1002/gps.1713.CrossRefGoogle ScholarPubMed
Fossey, J., Lee, L. and Ballard, C. (2002). Dementia care mapping as a research tool for measuring quality of life in care settings: psychometric properties. International Journal of Geriatric Psychiatry, 17, 1064–1070. doi: 10.1002/gps.708.CrossRefGoogle ScholarPubMed
Freund, A. and Baltes, P. B. (2003). Pour un développement et un vieillissement réussis: Sélection, optimisation et compensation. Revue Quebecoise de Psychologie, 24, 27–52.Google Scholar
Garand, L., Lingler, J. H., Conner, K. O. and Dew, M. A. (2009). Diagnostic labels, stigma, and participation in research related to dementia and mild cognitive impairment. Research in Gerontological Nursing, 2, 112–121. doi: 10.3928/19404921-20090401-04.Google Scholar
Gräske, J., Fischer, T., Kuhlmey, A. and Wolf-Ostermann, K. (2012). Dementia-specific quality of life instruments and their appropriateness in shared-housing arrangements–a literature study. Geriatric Nursing, 33, 204–216. doi: 10.1016/j.gerinurse.2012.01.001.Google Scholar
Guyatt, G. H., Feeny, D. H. and Patrick, D. L. (1993). Measuring health-related quality of life. Annals of Internal Medicine, 118, 622–629. doi: 10.7326/0003-4819-118-8-199304150-00009.Google Scholar
Howard, K. and Rockwood, K. (1995). Quality of life in Alzheimer's disease. Dementia, 6, 113–116. doi: DOI:10.1159/000106931.Google Scholar
Huang, H. L., Chang, M. Y., Tang, J. S., Chiu, Y. C. and Weng, L. C. (2009). Determinants of the discrepancy in patient- and caregiver-rated quality of life for persons with dementia. Journal of Clinical Nursing, 18, 3107–3118. doi: 10.1111/j.1365-2702.2008.02537.x.CrossRefGoogle ScholarPubMed
Jonker, C., Gerritsen, D. L., Bosboom, P. R. and Van Der Steen, J. T. (2004). A model for quality of life measures in patients with dementia: lawton's next step. Dementia & Geriatric Cognitive Disorders, 18, 159–164. doi: 10.1159/000079196.Google Scholar
Kasper, J. D., Black, B. S., Shore, A. D. and Rabins, P. V. (2009). Evaluation of the validity and reliability of the Alzheimer disease-related quality of life assessment instrument. Alzheimer Disease and Associated Disorders, 23, 275–284. doi: 10.1097/WAD.0b013e31819b02bc.Google Scholar
Kelly, C. A., Harvey, R. J. and Cayton, H. (1997). Drug treatments for Alzheimer's disease. British Medical Journal, 314, 693–694. doi: 10.1136/bmj.314.7082.693.Google Scholar
Kendrick, A. (1993). Repertory Grid Technique in the Assessment of Quality of Life in Patients with Epilepsy. London, England: University of London.Google Scholar
Kitwood, T. (1993). Person and process in dementia. International Journal of Geriatric Psychiatry, 8, 541–545. doi: 10.1002/gps.930080702.Google Scholar
Kitwood, T. and Bredin, K. (1992). Towards a theory of dementia care: personhood and well-being. Ageing & Society, 12, 269–287. doi: 10.1017/S0144686X0000502X.Google Scholar
Knapp, M. (2010). Dementia: a new global epidemic?. Maturitas, 67, 193–194. doi: 10.1016/j.maturitas.2010.06.015.CrossRefGoogle ScholarPubMed
Krabbe, P. F. (2008). Thurstone scaling as a measurement method to quantify subjective health outcomes. Medical Care, 46, 357–365. doi: 10.1097/MLR.0b013e31815ceca9.Google Scholar
Lam, C. L. K. (2010). Subjective quality of life measures – general principles and concepts. In Preedy, V. R. and Watson, R. R. (eds.), Handbook of Disease Burdens and Quality of Life Measures (vol. 1, pp. 382–399). New York: Springer.Google Scholar
Lawton, M. P. (1991). A multidimensional view of quality of life in frail elders. In Birren, J. E., Lubben, J. E., Rowe, J. C. and Deutchman, D. E. (eds.), The Concepts and Measurement of Quality of Life in the Frail Elderly (pp. 4–27). New York: Academic Press.Google Scholar
Lawton, M. P. (1994). Quality of life in Alzheimer disease. Alzheimer Disease & Associated Disorders, 8, 138–150.Google Scholar
Lazarus, R. S. and Folkman, S. (1984). Stress, Appraisal and Coping. New York: Springer Publishing Company.Google Scholar
Leon-Salas, B., Logsdon, R. G., Olazaran, J. and Martinez-Martin, P. (2011). Psychometric properties of the Spanish QoL-AD with institutionalized dementia patients and their family caregivers in Spain. Aging & Mental Health, 15, 775–783. doi: 10.1080/13607863.2011.562183.Google Scholar
Logsdon, R. G., Gibbons, L. E., McCurry, S. M. and Teri, L. (1999). Quality of life in Alzheimer's disease: patient and caregiver reports. Journal of Mental Health and Aging, 5, 21–32.Google Scholar
Logsdon, R. G., Gibbons, L. E., McCurry, S. M. and Teri, L. (2002). Assessing quality of life in older adults with cognitive impairment. Psychosomatic Medicine, 64, 510–519. doi: 10.1097/00006842-200205000-00016.Google Scholar
Lucas-Carrasco, R., Gomez-Benito, J., Rejas, J. and Brod, M. (2011). The Spanish version of the dementia quality of life questionnaire: a validation study. Aging & Mental Health, 15, 482–489. doi: 10.1080/13607863.2010.543658.Google Scholar
Lucas-Carrasco, R., Gomez-Benito, J., Rejas, J. and Ott, B. R. (2013). The cornell-brown scale for quality of life in dementia: spanish adaptation and validation. Alzheimer Disease and Associated Disorders, 27, 44–50. doi: 10.1097/WAD.0b013e318242040b.Google Scholar
Martin-Cook, K., Hynan, L. S., Rice-Koch, K., Svetlik, D. A. and Weiner, M. F. (2005). Responsiveness of the quality of life in late-stage dementia scale to psychotropic drug treatment in late-stage dementia. Dementia and Geriatric Cognitive Disorders, 19, 82–85. doi: 10.1159/000082353.Google Scholar
Moos, R. H. and Tsu, V. D. (1977). The crisis of physical illness: an overview. In Moos, R. H. (eds.), Coping with Physical Illness (pp. 3–21). New York: Plenum Medical Book Company.Google Scholar
Mulhern, B. et al. (2012). Improving the measurement of QALYs in dementia: developing patient- and carer-reported health state classification systems using Rasch analysis. Value in Health, 15, 323–333. doi: 10.1016/j.jval.2011.09.006.CrossRefGoogle ScholarPubMed
Mulhern, B. et al. (2013). Development of DEMQOL-U and DEMQOL-PROXY-U: generation of preference-based indices from DEMQOL and DEMQOL-PROXY for use in economic evaluation. Health Technology Assessment, 17, 1–140. doi: 10.3310/hta17050.Google Scholar
Naglie, G. (2007). Quality of life in dementia. The Canadian Journal of Neurological Sciences, 34, S57–61.Google Scholar
Novella, J.-L. et al. (2012). Qualité de vie et démence: état des connaissances [Quality of life in dementia: state of the knowledge]. Gériatrie et psychologie neuropsychiatrie du vieillissement, 10, 365–372.Google Scholar
Patrick, D. L. and Erickson, P. (1993). Concepts of health-related quality of life. In Patrick, D. L. and Erickson, P. (eds.), Health Status and Health Policy (pp. 76–112). New York: Oxford University Press.Google Scholar
Perales, J., Cosco, T. D., Stephan, B. C., Haro, J. M. and Brayne, C. (2013). Health-related quality-of-life instruments for Alzheimer's disease and mixed dementia. International Psychogeriatrics, 25, 691–706. doi: 10.1017/S1041610212002293.Google Scholar
Porzsolt, F. et al. (2004). A new instrument to describe indicators of well-being in old-old patients with severe dementia-the Vienna list. Health & Quality of Life Outcomes, 2, 10. doi: 10.1186/1477-7525-2-10.CrossRefGoogle ScholarPubMed
Rabins, P. V. and Black, B. S. (2007). Measuring quality of life in dementia: Purposes, goals, challenges and progress. International Psychogeriatrics, 19, 401–407. doi: 10.1017/S1041610207004863.Google Scholar
Rabins, P. V., Kasper, J. D., Kleinman, L., Black, B. S. and Patrick, D. L. (1999). Concepts and methods in the development of the ADRQL: an instrument for assessing health-related quality of life in persons with Alzheimer's disease. Journal of Mental Health and Aging, 5, 33–48.Google Scholar
Ready, R. E. and Ott, B. R. (2003). Quality of life measures for dementia. Health & Quality of Life Outcomes, 1, 11. doi: 10.1186/1477-7525-1-11.CrossRefGoogle ScholarPubMed
Ready, R. E., Ott, B. R., Grace, J. and Fernandez, I. (2002). The cornell-brown scale for quality of life in dementia. Alzheimer Disease and Associated Disorders, 16, 109–115. doi: 10.1097/00002093-200204000-00008.Google Scholar
Salek, M. S., Schwartzberg, E. and Bayer, A. J. (1996). Evaluating health-related quality of life in patients with dementia: development of a proxy self-administred questionnaire [abstract]. Pharmacy World and Science, 18, A6.Google Scholar
Salek, S. A., Walker, M. D. and Bayer, A. J. (1999). The community dementia quality of life profile (CDQLP): a factor analysis [abstract]. Quality of Life Research, 8, 660.Google Scholar
Salek, S. S., Walker, M. D. and Bayer, A. J. (1998). A review of quality of life in Alzheimer's disease. Part 2: issues in assessing drug effects. Pharmacoeconomics, 14, 613–627. doi: 10.2165/00019053-199814060-00003.Google Scholar
Schölzel-Dorenbos, C. J. et al. (2007). Evaluating the outcome of interventions on quality of life in dementia: selection of the appropriate scale. International Journal of Geriatric Psychiatry, 22, 511–519. doi: 10.1002/gps.1719.Google Scholar
Schölzel-Dorenbos, C. J., Arons, A. M., Wammes, J. J., Rikkert, M. G. and Krabbe, P. F. (2012). Validation study of the prototype of a disease-specific index measure for health-related quality of life in dementia. Health & Quality of Life Outcomes, 10, 118.Google Scholar
Selai, C. E., Trimble, M. R., Rossor, M. N. and Harvey, R. J. (2001). Assessing quality of life in dementia: preliminary psychometric testing of the quality of life assessment schedule (QOLAS). Neuropsychological Rehabilitation, 11, 219–243. doi: 10.1080/09602010042000033.CrossRefGoogle Scholar
Selai, C. and Trimble, M. R. (1999). Assessing quality of life in dementia. Aging & Mental Health, 3, 101–111. doi: 10.1080/13607869956253.Google Scholar
Shearer, J., Green, C., Ritchie, C. W. and Zajicek, J. P. (2012). Health state values for use in the economic evaluation of treatments for Alzheimer's disease. Drugs Aging, 29, 31–43. doi: 10.2165/11597380-000000000-00000.Google Scholar
Sloane, P. D. et al. (2007). Dementia care mapping as a research tool. International Journal of Geriatric Psychiatry, 22, 580–589. doi: 10.1002/gps.708.Google Scholar
Smith, S. C. et al. (2005a). Measurement of health-related quality of life for people with dementia: development of a new instrument (DEMQOL) and an evaluation of current methodology. Health Technology Assessment, 9, 1–93.Google Scholar
Smith, S. C. et al. (2005b). What constitutes health-related quality of life in dementia? development of a conceptual framework for people with dementia and their carers. International Journal of Geriatric Psychiatry, 20, 889–895. doi: 10.1002/gps.1374.CrossRefGoogle ScholarPubMed
Smith, S. C. et al. (2007). Development of a new measure of health-related quality of life for people with dementia: DEMQOL. Psychological Medicine, 37, 737–746. doi: 10.1017/S0033291706009469.Google Scholar
Steeman, E., Godderis, J., Grypdonck, M., De Bal, N. and Dierckx de Casterle, B. (2007). Living with dementia from the perspective of older people: is it a positive story?. Aging & Mental Health, 11, 119–130. doi: 10.1080/13607860600963364.Google Scholar
Taillefer, M.-C., Dupuis, G., Roberge, M.-A. and Le May, S. (2003). Health-related quality of life models: systematic review of the literature. Social Indicators Research, 64, 293–323. doi: 10.1023/A:1024740307643.Google Scholar
Terada, S. et al. (2002). Development and evaluation of a health-related quality of life questionnaire for the elderly with dementia in Japan. International Journal of Geriatric Psychiatry, 17, 851–858. doi: 10.1002/gps.711.Google Scholar
Trigg, R., Jones, R. W. and Skevington, S. M. (2007a). Can people with mild to moderate dementia provide reliable answers about their quality of life? Age & Ageing, 36, 663–669. doi: 10.1093/ageing/afm077.Google Scholar
Trigg, R., Skevington, S. M. and Jones, R. W. (2007b). How can we best assess the quality of life of people with dementia? The Bath assessment of subjective quality of life in dementia (BASQID). The Gerontologist, 47, 789–797. doi: 10.1093/geront/47.6.789.Google Scholar
Van Dijkhuizen, M., Clare, L. and Pearce, A. (2006). Striving for connection: appraisal and coping among women with early-stage Alzheimer's disease. Dementia, 5, 73–94. doi: 10.1177/1471301206059756.Google Scholar
Walker, M. D., Salek, S. S. and Bayer, A. J. (1998). A review of quality of life in Alzheimer's disease. Part 1: issues in assessing disease impact. Pharmacoeconomics, 14, 499–530. doi: 10.2165/00019053-199814050-00004.Google Scholar
Weiner, M. F., Martin-Cook, K., Svetlik, D. A., Saine, K., Foster, B. and Fontaine, C. S. (2000). The quality of life in late-stage dementia (QUALID) scale. Journal of the American Medical Directors Association, 1, 114–116.Google Scholar
Yamamoto-Mitani, N., Abe, T., Okita, Y., Hayashi, K., Sugishita, C. and Kamata, K. (2002). Development of a Japanese quality of life instrument for older adults experiencing dementia (QLDJ). The International Journal of Aging & Human Development, 55, 71–95. doi: 10.2190/KUTN-74X3-27CX-NUMK.CrossRefGoogle ScholarPubMed
Yamamoto-Mitani, N., Abe, T., Okita, Y., Hayashi, K., Sugishita, C. and Kamata, K. (2004). The impact of subject/respondent characteristics on a proxy-rated quality of life instrument for the Japanese elderly with dementia. Quality of Life Research, 13, 845–855. doi: 10.1023/B:QURE.0000021691.21667.1f.Google Scholar