Factor structure and measurement invariance of the older people’s quality of life scale

Accurate quality of life assessment is crucial for the development of our understanding of positive ageing. The Older People’s Quality of Life Scale (OPQOL) is a measure developed for use with older adult samples; however, its factor structure remains unclear and measurement consistency across population subgroups has not yet been confirmed. 432 Australian older adults aged 65+ completed the OPQOL as part of a telephone survey. An exploratory factor analysis (EFA; Mplus) was conducted to clarify the factor structure, while confirmatory factor analyses (CFA) were run to confirm measurement invariance across age and gender subgroups. Application of a CFA to the original 32-item OPQOL yielded poor model fit. A subsequent EFA suggested a six-factor solution incorporating 23 of the original items. Measurement invariance of the proposed model was determined via a series of CFAs that demonstrated acceptable-to-good model fit and supported configural, metric and scalar invariance across both age and gender. A shorter version of the OPQOL that provides both a total and subscale scores is proposed, but the model requires further confirmation via CFA in other English-speaking samples. This version of the OPQOL demonstrates consistency of measurement across age and gender, which suggests that scores can be meaningfully compared between groups.