Journal article
Assessing the agreement between self- and proxy-reported responses for measuring health-related quality of life in people with dementia using the Alzheimer’s Disease Five Dimensions instrument
Value in Health, Vol.First online(9)
15/05/2026
Appears in Recent Faculty of Health Publications
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Abstract
Background
The level of agreement between utility values derived from self- and proxy-reports, assessed using the preference-based health-related quality of life (HRQoL) instrument, the Alzheimer’s Disease Five Dimensions (AD-5D), remains unclear. We aimed to investigate the agreement between self- and proxy-reported HRQoL, measured using the AD-5D, a dementia-specific, preference-based HRQoL instrument.
Methods
The data comprise 77 Australian dyads of people with dementia and their caregivers. The agreement between AD-5D utility values derived from self- and proxy-reports was analysed using a Bland-Altman plot. The ordinary least squares regression technique was employed to identify factors associated with the AD-5D utility value sets and to assess agreement between the resulting AD-5D utility values derived from self- and proxy-reports.
Results
The mean AD-5D utility value derived from self-reports (0.667) was higher than the value derived from proxy-reports (0.523). The Bland-Altman plot shows that 7.79% of the differences in AD-5D utility values fell outside the limits of agreement. The regression results indicated that the AD-5D utility value derived from self-reports for people with dementia aged 80 years or older was, on average, 0.20 points lower (β = 0.20, SE = 0.10) than that for people with dementia aged less than 70 years.
Conclusion
Utility values derived from self-reports were higher than those derived from caregiver proxy-reports. While proxy reporting is a necessary alternative when self-reporting is not feasible, these perspectives are not interchangeable. Future economic evaluations should incorporate sensitivity analyses to account for this systematic 'proxy-gap'.
Details
- Title
- Assessing the agreement between self- and proxy-reported responses for measuring health-related quality of life in people with dementia using the Alzheimer’s Disease Five Dimensions instrument
- Creators
- Syed A Keramat - The University of QueenslandTiet-Hanh Dao-Tran - The University of QueenslandKim-Huong Nguyen - The University of QueenslandAlyssa Welch - The University of QueenslandTracy Comans - The University of Queensland
- Publication Details
- Value in Health, Vol.First online(9)
- Publisher
- Elsevier; NEW YORK
- Grant note
- his study was supported by funding provided by the National Health and Medical Research Council (NHMRC) Partnership Centre on Dealing with Cognitive and Related Functional Decline in Older People (Grant no. GNT9100000). Professor Tracy Comans was supported by an NHMRC Boosting Dementia Research Fellowship. The contents of the published materials are solely the responsibility of the University of Queensland and the individual authors identified and do not reflect the views of the NHMRC or any other funding bodies or the funding partners.
- Identifiers
- 991013377250702368
- Academic Unit
- Faculty of Health
- Language
- English
- Resource Type
- Journal article