Psychometric properties of the EUROHIS-QOL 8-item index (WHOQOL-8) in a Brazilian sample

Abstract

Objective: To test the psychometric properties of the EUROHIS-QOL 8-item index in a Brazilian sample. Methods: The sample consisted of 151 patients and 174 healthy controls (n=325). Several psychometric properties were tested. Results: Reliability showed good internal consistency (Cronbach’s alpha = 0.81). The measure showed good discriminant validity between patients and healthy controls (mean1 = 3.32, SD1 = 0.70; mean2 = 3.77, SD2 = 0.63, t = 6.12, p < 0.001). Convergent validity showed significant correlations (p < 0.001) between the EUROHIS-QOL 8-item index and all domains of the WHOQOL-Bref (overall r = 0.47; general health r = 0.54; physical r = 0.69; psychological r = 0.62; social relationship r = 0.55; environment r = 0.55) and between the EUROHIS-QOL 8-item index and the domains of the SF-36, except for the social domain (p = 0.38). On Rasch analysis of unidimensionality, general fit measures showed adequate performance. The EUROHIS-QOL 8-item index also showed good fit on confirmatory factor analysis (CFA) (chi-square = 18.46, degrees of freedom [df] = 15; comparative fit index [CFI] = 0.99; root mean square error of approximation [RMSEA] = 0.03; goodness of fit index [gfi] = 0.99; root mean square residual [RMR] = 0.03; p = 24). Conclusion: The EUROHIS-QOL 8-item index showed good psychometric properties. It is a reliable quality of life measure that can be used in Brazilian populations.