Psychometric properties and confirmatory factor analysis of the CASP-19, a measure of quality of life in early old age: the HAPIEE study
Abstrakt
Objectives: The aim was to assess the reliability and validity of the quality of life (QoL) instrument CASP-19, and three shorter versions of CASP-12 in large population sample of older adults from the HAPIEE (Health, Alcohol, and Psychosocial factors In Eastern Europe) study. Methods: From the Czech Republic, Russia, and Poland, 13,210 HAPIEE participants aged 50 or older completed the retirement questionnaire including CASP-19 at baseline.
Three shorter 12-item versions were also derived from original 19-item instrument. Psychometric validation used confirmatory factor analysis, Cronbach's alpha, Pearson's correlation, and construct validity.
Results: The second-order four-factor model of CASP-19 did not provide a good fit to the data. Two-factor CASP-12v.3 including residual covariances for negative items to account for the method effect of negative items had the best fit to the data in all countries (CFI = 0.98, TLI = 0.97, RMSEA = 0.05, and WRMR = 1.65 in the Czech Republic; 0.96, 0.94, 0.07, and 2.70 in Poland; and 0.93, 0.90, 0.08, and 3.04 in Russia).
Goodness-of-fit indices for the two-factor structure were substantially better than second-order models. Conclusions: This large population-based study is the first validation study of CASP scale in Central and Eastern Europe (CEE), which includes a general population sample in Russia, Poland, and the Czech Republic.
The results of this study have demonstrated that the CASP-12v.3 is a valid and reliable tool for assessing QoL among adults aged 50years or older. This version of CASP is recommended for use in future studies investigating QoL in the CEE populations.