Health-related quality of life in people with advanced dementia: a comparison of EQ-5D-5L and QUALID instruments
Assessing health-related quality of life (HRQOL) in people with advanced dementia is challenging but important for informed decision-making. Proxy measurement of this construct is difficult and is often rated lower than self-report. Accurate proxy rating of quality of life in dementia is related to identification of concepts important to the person themselves, as well as the sensitivity of the measures used. The main aim of this study was to compare the performance of two instruments—QUALID and EQ-5D-5L—on measuring HRQOL in people with advanced dementia.
In a sub-study nested within a cluster-RCT we collected proxy(nurse)-completed EQ-5D-5L and QUALID measures at baseline, 3, 6, 9 and 12 months’ follow-up for people with advanced dementia, residing in 20 nursing homes across Australia. Spearman’s rank correlations, partial correlations and linear regressions were used to assess the relationship between the HRQOL instrument scores and their changes over time.
The mean weight from 284 people for the EQ-5D-5L and QUALID at baseline were 0.004 (95% CI − 0.026, 0.033) and 24.98 (95% CI 24.13, 25.82), respectively. At 12 months’ follow-up, 115 participants remained alive. EQ-5D-5L weights and QUALID scores at baseline and at follow-up were moderately correlated (r = − 0.437; p < 0.001 at 12 months). Changes within QUALID and EQ-5D-5L across the same follow-up periods were also correlated (r = − 0.266; p = 0.005). The regression analyses support these findings.
Whilst these quality of life instruments demonstrated moderate correlation, the EQ-5D-5L does not appear to capture all aspects of quality of life that are relevant to people with advanced dementia and we cannot recommend the use of this instrument for use within this population. The QUALID appears to be a more suitable instrument for measuring HRQOL in people with severe dementia, but is not preference-based, which limits its application in economic evaluations of dementia care.
KeywordsDementia Health-related Quality of Life QALY QUALID EQ-5D-5L Proxy Advanced dementia
This study was funded by the Australian Department of Health (previously Department of Health and Ageing) (http://www.health.gov.au/).
Compliance with ethical standards
Conflict of interest
Elizaveta Sopina declares that she has no conflict of interest. Lynn Chenoweth declares that she has no conflict of interest. Tim Luckett declares that he has no conflict of interest. Meera Agar declares that she has no conflict of interest. Georgina M Luscombe declares that she has no conflict of interest. Patricia M. Davidson declares that she has no conflict of interest. Constance D Pond declares that she has been on an advisory committee on dementia for Elli-Lilly, has received speaker fees for speaking about dementia to Australian General Practitioners, Primary Health Networks and Alzheimer’s Australia, as well as airfares and accommodation to prepare educational material on dementia for General Practitioners. Jane Phillips declares that she has no conflict of interest. Stephen Goodall declares that he has no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Human Research Ethics Committees of the University of NSW, University of Technology Sydney, Queensland University of Technology approved the trial. The trial was registered under trial ID no ACTRN12612001164886 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=362912.
Human and animal rights
This article does not contain any studies with animals performed by any of the authors.
Informed consent was obtained from family members with legal authority on behalf of all study participants.
- 1.de Wit, M., & Hajos, T. (2013). Health-related quality of life. In M. D. Gellman & J. R. Turner (Eds.), Encyclopedia of behavioral medicine (pp. 929–931). New York: Springer.Google Scholar
- 4.Smith, S., et al. (2005) 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 (Winchester, England). 9(10): 1–93.Google Scholar
- 6.Kind, P. (1996). The EuroQoL instrument: an index of health-related quality of life. Quality of Life and Pharmacoeconomics in Clinical Trials, 2, 191–201.Google Scholar
- 7.Reisberg, B. (1988). Functional assessment staging (FAST). Psychopharmacology Bulletin, 24(4), 653–659.Google Scholar
- 17.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(1), 15–24.CrossRefGoogle Scholar
- 18.Logsdon, R. G., et al. (1999). Quality of life in Alzheimer’s disease: Patient and caregiver reports. Journal of Mental Health and Aging, 5, 21–32.Google Scholar
- 19.Agar, M., et al. (2015). Pragmatic cluster randomised controlled trial of facilitated family case conferencing compared with usual care for improving end of life care and outcomes in nursing home residents with advanced dementia and their families: The IDEAL study protocol. BMC Palliative Care, 14(1), 63.CrossRefGoogle Scholar
- 26.Weiner, M. F., et al. (2000). The quality of life in late-stage dementia (QUALID) scale. Journal of the American Medical Directors Association, 1(3), 114–116.Google Scholar
- 28.StataCorp (2015). Stata statistical software: Release 14. College Station: StataCorp LP.Google Scholar
- 32.Rokstad, A. M. M., et al. (2013). The effect of person-centred dementia care to prevent agitation and other neuropsychiatric symptoms and enhance quality of life in nursing home patients: A 10-month randomized controlled trial. Dementia and Geriatric Cognitive Disorders, 36(5–6), 340–353.CrossRefGoogle Scholar
- 35.Sopina, E., et al. (2017). Cost-effectiveness of a randomised trial of physical activity in Alzheimer’s disease: A secondary analysis exploring patient and proxy-reported health-related quality of life measures in Denmark. British Medical Journal Open, 7(6), e015217.Google Scholar