Validating the Well-being of Older People (WOOP) instrument in China

Abstract

Introduction: So far, generic health related quality of life (HRQoL) has been used for estimating utility value, which then be used for calculating quality adjust life years (QALY). HRQoL measures may not capture many of the relevant and important aspects of quality of life other than health. Well-being of older people (WOOP) was first developed in the Netherlands to measure the well-being of older people; this study aims to validate this new measure in China. Methods: Between July and August 2022, a cross-sectional study was conducted in a convenient sample of 500 older people in Southwestern China. Consented older people reported their demographic information and the simplified Chinese version of WOOP measure using paper and pencil. The acceptability of WOOP was examined by percent of missing responses. Then, using the data without any missing responses, we examined the acceptability, item responses distributions, pairwise spearman correlations, exploratory factor analysis and known-group validity of WOOP. Results: Among the nine items, three of them had more than 10% of missing responses. The response distributions of 9 items in WOOP were overall good without signs of ceiling effects and floor effects. There was not high correlations among WOOP items. A two-factor EFA model suggested WOOP items can be categorized into either internal wellbeing or external wellbeing. Good known-group validity results were found reported. Discussion: Some WOOP items may not be easily understood by a small proportion of rural residents. Other results suggested WOOP to be valid instrument for measuring the well-being of elderly in China. The availability of WOOP enables the measurement of wellbeing related utility.