Measuring quality of life in older migrants: assessing the construct and convergent validity of the CASP-12 among older Chinese migrants

Objectives: Many people are ageing outside of their countries of origin, and the older adult population is becoming increasingly diverse globally. Although research with older migrants is growing, key constructs, such as quality of life (QOL), are routinely measured with instruments developed with the native population within a single country. Understanding the cultural appropriateness and validity of these measures should be a key focus for research with older migrants to ensure findings reported are based on reliable estimates. In this study, we investigated the validity of the CASP-12, an older adult-specific QOL scale, with a sample of older Chinese migrants in Aotearoa New Zealand. Methods: Survey data were collected from 245 older Chinese migrants. The CASP-12 and criterion measures assessing QOL, self-reported health, income adequacy, length of residence, perceived language barriers, household composition and education were administered. Results: Confirmatory factor analyses confirmed the three-factor structure of the CASP-12. Control & Autonomy, Pleasure and Self-realisation emerged as independent factors. A significant method effect was, however, identified in connection with reverse-scored items of the Control & Autonomy subscale, indicating a potential response bias. The CASP-12 and its subscales related to criterion measures in expected ways. Conclusions: There is partial evidence for the validity and reliability of the CASP-12 as a QOL measure to be used with older Chinese migrants. The presence of a method effect, however, suggests that estimates related to the Control & Autonomy subscale are impacted by bias, and revision of the CASP-12 may be necessary in the future.