Quality of life in Polish respondents: psychometric properties of the Polish WHOQOL-Bref.

The aim of this study was to examine the validity and reliability of the Polish WHOQOL - Bref in a sample of 908 respondents. The Bref is a generic quality of life (QoL) instrument designed for cross - cultural use. Correlational and multivariate analyses confirmed the relevancy of individual items and domains supporting the construct validity of the scale. Multiple regression analyses of the domain scores with two overall questions (dependent variable) showed that all four domains made a significant contribution in explaining the variance in overall QoL. The psychological domain made the strongest contribution (unstandardized B coefficient = 0.10, r2 = 0.41), followed by the social, environmental and physical domains. When overall health satisfaction was considered as the dependent variable, the physical domain contributed most strongly (unstandardized B coefficient = 0.21, r2= 0.43) followed by the psychological and environmental domains. Exploratory factor analyses resulted in a four factors solution with 24 items explaining 49.6% of the cumulative variance. Confirmatory factor analyses lended marginal support for the goodness of fit of the four-domain model. The physical domain was found to be strongest in differentiating between unhealthy and healthy subjects, followed by psychological and social domains. Acceptable internal consistency was shown with Cronbach's alpha coefficients being greater than 0.70 for all domains with the exception of the social domain. Further exploration of the scales validity and conceptual clarity need further testing in Polish and international samples.