An investigation of the structural relationships among well-being and quality of life components

What is "quality of life"? Many conceptual models have been proposed; however, what is seen less often is the testing of such models in terms of the discriminant and convergent properties of model components. A generic quality of life model (Evans, 1994) including personality characteristics (self-esteem, dispositional optimism, neuroticism, extraversion), subjective well-being (positive and negative affect, global and domain life satisfaction), and quality of life outcomes (behavioural quality of life, health-related quality of life) was used as a guiding framework in order to investigate various hypothesized directional relationships. Pathology based measures (anxiety and depression) were also included for discriminant validity purposes. Accordingly, a self-report assessment battery was designed and administered to two adult, community samples of London, Ontario (n = 314, n = 273). The second independent sample was used solely for cross-validation purposes. Empirical testing proceeded via exploratory (factor analysis) and confirmatory (structural equation modelling) methods. Examination of zero-order correlations generally revealed moderate to high correlations both within and between the several classes of well-being/quality of life variables. This was further reinforced by exploratory and confirmatory factor analyses. Exploratory factor analysis revealed a 3 factor solution (accounting for 48.3% of the variance) with Psychological Well-being (26.6% of the variance), Physical Well-being (13.3% of the variance), and Occupational Well-being (8.4% of the variance) as the three factors. Testing the hypothesized structural relationships among well-being/quality of life components met with serious methodological challenge, namely, multi-collinearity. Relying on confirmatory factor analysis, the hypothesized and nested measurement models solely within the previously identified Psychological Well-being component led to a 3 factor model: Personality/Affectivity, Life Satisfaction (cognitive-evaluative dimension), and Behavioural Quality of Life. A hierarchical model with 1 higher-order factor ("Overall Quality of Life") and the 3 group factors ("Personality/Affectivity", "Life Satisfaction", "Behavioural Quality of Life") offered an acceptable fit to the data (CFI = .906, GFI = .850, AGFI = .811). Attempts to cross-validate these findings were mildly successful. The results of these quantitative approaches to assessing the properties of the quality of life construct have particular implications for the conceptualization and assessment of quality of life across a wide variety of settings.