RESUMEN
PURPOSE: This study aimed to examine the psychometric performance of the EQ-5D-5L in informal caregivers of people with dementia. METHODS: Data were obtained from an online survey administered to informal caregivers of people with dementia in Australia. Known-group comparisons were examined by formulating 15 a priori hypotheses, where a difference was made between weak and strong hypotheses. Group comparisons were tested using the non-parametric Wilcoxon-rank and the Kruskal-Wallis test, as well as regression analysis. Floor and ceiling effects were considered to be present if more than 15% of respondents achieved the lowest or highest possible score, respectively. RESULTS: In total, 212 informal caregivers of people with dementia were included in the analysis. On average, participants were 47 years old (SD: 17) and 61% of them were female. The mean EQ-5D-5L utility score was 0.88 (SD: 0.16) and the mean EQ-VAS was 72.47 (SD: 17.86). While there was no floor effect, 26% reported full health. Nine strong and three weak hypotheses were confirmed, supporting the ability of the EQ-5D-5L to discriminate between groups with respect to: self-reported health status, happiness levels, presence of mental or physical health conditions, ability to engage in enjoyable activities, and availability of support. CONCLUSION: Findings provide supporting evidence for the EQ-5D-5L in terms of its discriminant validity in informal caregivers of patients with dementia. However, the present ceiling effect suggests that the sensitivity of the EQ-5D-5L to detect improvements may be limited. Further studies are warranted examining other psychometric criteria, including reliability and responsiveness to change.
RESUMEN
PURPOSE: Proxy assessment can be elicited via the proxy-patient perspective (i.e., asking proxies to assess the patient's quality of life (QoL) as they think the patient would respond) or proxy-proxy perspective (i.e., asking proxies to provide their own perspective on the patient's QoL). This review aimed to identify the role of the proxy perspective in explaining the differences between self-rated and proxy-rated QoL in people living with dementia. METHODS: A systematic literate review was conducted by sourcing articles from a previously published review, supplemented by an update of the review in four bibliographic databases. Peer-reviewed studies that reported both self-reported and proxy-reported mean QoL estimates using the same standardized QoL instrument, published in English, and focused on the QoL of people with dementia were included. A meta-analysis was conducted to synthesize the mean differences between self- and proxy-report across different proxy perspectives. RESULTS: The review included 96 articles from which 635 observations were extracted. Most observations extracted used the proxy-proxy perspective (79%) compared with the proxy-patient perspective (10%); with 11% of the studies not stating the perspective. The QOL-AD was the most commonly used measure, followed by the EQ-5D and DEMQOL. The standardized mean difference (SMD) between the self- and proxy-report was lower for the proxy-patient perspective (SMD: 0.250; 95% CI 0.116; 0.384) compared to the proxy-proxy perspective (SMD: 0.532; 95% CI 0.456; 0.609). CONCLUSION: Different proxy perspectives affect the ratings of QoL, whereby adopting a proxy-proxy QoL perspective has a higher inter-rater gap in comparison with the proxy-patient perspective.