Testing the factor structure of the Family Quality of Life Survey – 2006
Article first published online: 20 APR 2011
© 2011 The Authors. Journal of Intellectual Disability Research © 2011 Blackwell Publishing Ltd
Journal of Intellectual Disability Research
Special Issue: Part Two: Family Quality of Life (Edited by Ralph Kober and Mian Wang)
Volume 56, Issue 1, pages 17–29, January 2012
How to Cite
Isaacs, B., Wang, M., Samuel, P., Ajuwon, P., Baum, N., Edwards, M. and Rillotta, F. (2012), Testing the factor structure of the Family Quality of Life Survey – 2006. Journal of Intellectual Disability Research, 56: 17–29. doi: 10.1111/j.1365-2788.2011.01392.x
- Issue published online: 15 DEC 2011
- Article first published online: 20 APR 2011
- Accepted 13 January 2011
- developmental disabilities;
- family quality of life;
- intellectual disabilities;
Background Although the Family Quality of Life Survey – 2006 (FQOLS-2006) is being used in research, there is little evidence to support its hypothesised domain structure. The purpose of this study was to test the domain structure of the survey using confirmatory factor analysis.
Method Samples from Australia, Canada, Nigeria and the USA were analysed using structural equation modelling. The data from Australia, Canada and the USA were combined on the assumption that these countries are similar, at least to some degree, in economic development, language and culture. The Nigerian data were analysed on its own. The analysis was undertaken in two phases. First, the hypothesis that each of nine domains of the FQOLS-2006 is a unidimensional construct that can reliably measure the dimensions Importance, Stability, Opportunities, Attainment, Stability and Satisfaction was tested. Second, the hypothesis that family quality of life (FQoL) is a single latent construct represented by the nine domains measured in the FQOLS-2006 was tested.
Results In the first phase of the analysis, the Importance dimension was dropped because of skewness and lack of variance. The Stability dimension did not fit well within the individual domain model in both the Nigerian and the combined three countries' data. When Importance and Stability were excluded, the individual domain models showede good or acceptable fit when error variances of some dimensions were allowed to correlate. In the second phase of the analysis, the overall model, FQoL, represented by the nine domains of the FQOLS-2006 showed good fit in both data sets.
Conclusions The conceptual model of the FQOLS-2006 was supported with some qualifications. Each domain on the survey can be reliably measured by four dimensions Opportunities, Initiative, Attainment and Satisfaction. The dimensions of Importance and Stability, however, did not fit. Data reported on these dimensions from past and current studies should be interpreted with caution. The construct of FQoL is also reliably measured by the domains of the FQOLS-2006. Further research into the psychometric properties of the survey, particularly from a cross-cultural perspective, is needed.