Reliability of the quality of life-aged care consumers (QOL-ACC) and EQ-5D-5L among older people using aged care services at home.

PURPOSE: The Quality of Life-Aged Care Consumers (QOL-ACC), a valid preference-based instrument, has been rolled out in Australia as part of the National Quality Indicator (QI) program since April 2023 to monitor and benchmark the quality of life of aged care recipients. As the QOL-ACC is being used to collect quality of life data longitudinally as one of the key aged care QI indicators, it is imperative to establish the reliability of the QOL-ACC in aged care settings. Therefore, we aimed to assess the reliability of the QOL-ACC and compare its performance with the EQ-5D-5L. METHODS: Home care recipients completed a survey including the QOL-ACC, EQ-5D-5L and two global items for health and quality of life at baseline (T1) and 2 weeks later (T2). Using T1 and T2 data, the Gwet's AC2 and intra-class correlation coefficient (ICC) were estimated for the dimension levels and overall scores agreements respectively. The standard error of measurement (SEM) and the smallest detectable change (SDC) were also calculated. Sensitivity analyses were conducted for respondents who did not change their response to global item of quality of life and health between T1 and T2. RESULTS: Of the 83 respondents who completed T1 and T2 surveys, 78 respondents (mean ± SD age, 73.6 ± 5.3 years; 56.4% females) reported either no or one level change in their health and/or quality of life between T1 and T2. Gwet's AC2 ranged from 0.46 to 0.63 for the QOL-ACC dimensions which were comparable to the EQ-5D-5L dimensions (Gwet's AC2 ranged from 0.52 to 0.77). The ICC for the QOL-ACC (0.85; 95% CI, 0.77-0.90) was comparable to the EQ-5D-5L (0.83; 95% CI, 0.74-0.88). The SEM for the QOL-ACC (0.08) was slightly smaller than for the EQ-5D-5L (0.11). The SDC for the QOL-ACC and the EQ-5D-5L for individual subjects were 0.22 and 0.30 respectively. Sensitivity analyses stratified by quality of life and health status confirmed the base case results. CONCLUSIONS: The QOL-ACC demonstrated a good test-retest reliability similar to the EQ-5D-5L, supporting its repeated use in aged care settings. Further studies will provide evidence of responsiveness of the QOL-ACC to aged care-specific interventions in aged care settings.

Examining interrater agreement between self-report and proxy-report responses for the quality of life-aged care consumers (QOL-ACC) instrument.

BACKGROUND: Quality of life is an important quality indicator for health and aged care sectors. However, self-reporting of quality of life is not always possible given the relatively high prevalence of cognitive impairment amongst older people, hence proxy reporting is often utilised as the default option. Internationally, there is little evidence on the impact of proxy perspective on interrater agreement between self and proxy report. OBJECTIVES: To assess the impacts of (i) cognition level and (ii) proxy perspective on interrater agreement using a utility instrument, the Quality of Life-Aged Care Consumers (QOL-ACC). METHODS: A cross-sectional study was undertaken with aged care residents and family member proxies. Residents completed the self-report QOL-ACC, while proxies completed two proxy versions: proxy-proxy perspective (their own opinion), and proxy-person perspective (how they believe the resident would respond). Interrater agreement was assessed using quadratic weighted kappas for dimension-level data and concordance correlation coefficients and Bland-Altman plots for utility scores. RESULTS: Sixty-three residents (22, no cognitive impairment; 41, mild-to-moderate cognitive impairment) and proxies participated. In the full sample and in the mild-to-moderate impairment group, the mean self-reported QOL-ACC utility score was significantly higher than the means reported by proxies, regardless of perspective (p < 0.01). Agreement with self-reported QOL-ACC utility scores was higher when proxies adopted a proxy-person perspective. CONCLUSION: Regardless of cognition level and proxy perspective, proxies tend to rate quality of life lower than residents. Further research is needed to explore the impact of such divergences for quality assessment and economic evaluation in aged care.