Putting Wilson and Cleary to the test: analysis of a HRQOL conceptual model using structural equation modeling

Wilson and Cleary (1995) proposed a conceptual model of health-related quality of life (HRQOL) that integrates both biological and psychological aspects of health outcomes. There are five different levels in their model, namely, physiological factors, symptom status, functional health, general health perceptions, and overall quality of life. Their model has been widely applied to different populations, including patients living with cancer, Parkinson's disease, arthritis, and HIV+/AIDS. However, their conceptual model has only been partially examined. That is, the five major concepts have not been examined simultaneously. Using structural equation modeling (SEM), the Wilson and Cleary HRQOL model was validated in patients living with HIV from the AIDS Time-Oriented Health Outcomes Study. The results showed that the HRQOL model fit the data adequately, and the relationships between the constructs were all significant (at p<0.05 level). Based on the modification indexes, an alternative model linking symptom status directly with general health perceptions and overall quality of life was specified. Implication and limitation of the findings are discussed.