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Purpose: This study aims to evaluate the validity of current measurement models for the control, autonomy, self-realisation, and pleasure (CASP) measure of quality of life (QoL)—a second-order four-factor CASP-19 model and a second-order three-factor CASP-12 version—in a recent population survey. A previous large sample study did not report good fit for these measurement models. The study also aims to re-develop the model and propose a well-fitting alternative. Methods: To evaluate the current measurement models, confirmatory factor analysis (CFA) was used. A cross-sectional sample ( n = 6,823) representative of the Irish community-dwelling population aged 50 and over was obtained from the Irish Longitudinal Study of Ageing (TILDA). Model revision was based on descriptive statistics, exploratory factor analysis and examination of fit diagnostic statistics. Revised models were tested using CFA. Results: The results of the CFA did not support the validity of the established measurement models. A reformulated 12-item, two-factor model comprising control/autonomy and self-realisation/pleasure, with residual covariances for negatively worded items, had excellent fit to the data (χ 2 161.90, df = 44, p < 0.001; RMSEA = 0.03, 90 % CI 0.02–0.03), and a clearer conceptual rationale. The same model with one overall QoL factor had similar excellent fit. Conclusions: We recommend the use of the single-factor model (CASP-R12) when assessing overall quality of life. The dimensions of control/autonomy and self-realisation/pleasure can be examined separately by researchers interested in those constructs. Researchers using structural equation modelling can use the well-fitting measurement model outlined here including adjustment for residual covariances. [ABSTRACT FROM AUTHOR]

Background: This paper aimed to develop a short version of the 32-item Ageing Perceptions Questionnaire (APQ), a multi-dimensional measure based on Leventhal's self-regulation model. Ageing perceptions are a key area of interest for large-scale surveys of ageing populations. As these studies capture a broad range of health and social variables, included instruments need to be as concise as possible., Methods: Data from the Irish Longitudinal Study of Ageing (TILDA), a representative sample of community-dwelling individuals aged 50+ (n = 6,718), was used to revise the scale. Items for exclusion were identified by examining conceptual content, descriptive statistics, and by detecting sources of poor model fit using confirmatory factor analysis (CFA). Potential combinations of dimensions were also tested using CFA. Finally, we identified any dimensions that could be excluded without limiting the conceptual coverage and coherence of the scale. Model modifications were done sequentially and with regard to theoretical considerations. Internal consistency and construct validity of the concise scale were compared with the longer version., Results: Initially, 11 items were excluded on the basis of conceptual and empirical overlap with other items. CFA indicated that the negative-control and negative-consequences dimensions could be combined, allowing us to exclude a further item from this dimension. The 5-item timeline-cyclical dimension was also excluded, as it was less well-established conceptually and empirically than the other dimensions. The final 17-item, 5-dimension model was consistent with the original conceptual model and fit the data well (chi-sq = 1433.54, df(109), p < 0.01, RMSEA = 0.04, CFI = 0.97, TLI = 0.96)., Conclusions: The Brief-APQ (B-APQ) is a concise, multi-dimensional measure of ageing perceptions, which is psychometrically valid for use with the Irish population aged 50+. The concise version preserved the internal consistency and construct validity of the original. Its brevity makes it particularly suitable for use with large-scale adult population surveys. The psychometric analysis supports the application of the self-regulation model to ageing perceptions, but also the existence of distinct "physical decline" and "ongoing development" dimensions of perceptions.