Confirmatory factor analytical study of the WHOQOL-Bref: experience with Sudanese general population and psychiatric samples
1 Department of Psychiatry, Psychological Medicine Hospital, Gamal Abdul Naser Road, P.O. Box 4081, Safat, 13041 Kuwait
2 Department of Psychiatry, Faculty of Medicine, Kuwait University, Kuwait
3 Statistics Unit, Manpower Planning General Republic Program, Box 2822, Safat, 13029 Kuwait
BMC Medical Research Methodology 2007, 7:37 doi:10.1186/1471-2288-7-37Published: 1 August 2007
The widespread international use of the 26-item WHO Quality of Life Instrument (WHOQOL-Bref) necessitates the assessment of its factor structure across cultures. For, alternative factor models may provide a better explanation of the data than the WHO 4- and 6-domain models. The objectives of the study were: to assess the factor structure of the WHOQOL-Bref in a Sudanese general population sample; and use confirmatory factor analysis (CFA) and path analysis (PA) to see how well the model thus generated fits into the WHOQOL-Bref data of Sudanese psychiatric patients and their family caregivers.
In exploratory factor analysis (FA) with all items, data from 623 general population subjects were used to generate a 5-domain model. In CFA and PA, the model was tested on the data of 300 psychiatric outpatients and their caregivers, using four goodness of fit (GOF) criteria in Analysis of Moment Structures (AMOS). In the path relationships for our model, the dependent variable was the item on overall QOL (OQOL). For the WHO 6-domain model, the general facet on health and QOL was the dependent variable.
Two of the five factors ("personal relations" and "environment") from our FA were similar to the WHO's. In CFA, the four GOF criteria were met by our 5-domain model and WHO's 4-domain model on the psychiatric data. In PA, these two models met the GOF criteria on the general population data. The direct predictors of OQOL were our factors: "life satisfaction" and "sense of enjoyment". For the general facet, predictors were WHO domains: "environment", "physical health" and "independence'.
The findings support the credentials of WHO's 4-domain model as a universal QOL construct; and the impression that analysis of WHOQOL-Bref could benefit from including all the items in FA and using OQOL as a dependent variable. The clinical significance is that by more of such studies, a combination of domains from the WHO models and the local models would be generated and used to develop rigorous definitions of QOL, from which primary targets for subjective QOL interventions could be delineated that would have cross-cultural relevance.