PURPOSE: Several instruments assess different aspects of quality of life (QoL), the EQ-HWB is developed to capture broader health and wellbeing constructs. Established QoL measures such as the EQ-5D-5L, QOL-ACC, and ASCOT are widely used in older populations. Analysing dimensionality across these instruments can provide insight into the constructs they cover and their conceptual relationships. This study aimed to examine the dimensionality of the EQ-HWB both on its own and alongside pooled items from these measures, to identify its underlying structure and the extent of item overlap. METHODS: Analysis was conducted using data from 453 participants aged 65 years and above who completed all four instruments. Exploratory Factor Analysis (EFA) was conducted to identify the underlying factor structure. Factors were selected based on eigenvalues greater than one and scree plots. A correlation cut-off of 0.32 was applied to determine item loading on a given factor. Both oblique and orthogonal rotations were explored. EFA was conducted separately for the EQ-HWB and each instrument, as well as for the pooled items from all instruments. RESULTS: EFAs conducted separately for the EQ-HWB, and each instrument resulted in a 4-factor structure. However, EFA of all pooled items showed that the 5-factor structure provided a better model fit. The five factors identified were: emotional functioning, self-care and usual activities, leisure and enjoyment, cognition and senses, and pain. CONCLUSION: This study provides evidence on the dimensions of QoL captured by a select pool of health focused and broader QoL instruments in an older adult population. The results enhance understanding of the conceptual coverage of the EQ-HWB relative to other QoL measures.
Bahrampour et al. (Mon,) studied this question.