Multitrait-multimethod analysis of health-related quality-of-life measures.

Interest in health-related quality of life (HRQOL) is burgeoning and there has been a proliferation of self-report measures of HRQOL. However, only two instruments available for measuring HRQOL have been calibrated using empirically derived preferences; both are long and complex. This study tested a brief survey designed to concurrently assess HRQOL and preferences for different HRQOL states. Multitrait-multimethod (MTMM) analysis was used to evaluate the construct validity of the survey in a convenience sample of 116 persons. Two methods were used to assess six aspects of HRQOL: general health perceptions, meaningful activities, outlook on life, physical suffering, self-care activities, and social relationships. HRQOL preferences were assessed using two methods similar to those used for self-reports, as well as one additional method. The construct validity of self-reported HRQOL was supported. On the other hand, substantial method variance and little valid trait variance was observed for the HRQOL preferences. Results are discussed in terms of their implications for evaluating and measuring HRQOL and related preferences.