Accuracy of health-related quality of life assessment: what is the benefit of incorporating patients' preferences for domain functioning?

This study investigated the accuracy benefit of incorporating patients' preferences for domains of functioning into health-related quality of life (HRQOL) measurement. Using policy-capturing techniques, 102 medical outpatients judged the HRQOL of 16 scenarios describing varying levels of functioning in 3 domains. For each participant, regression analysis determined relative domain preferences and 2 decision models were built: one incorporating (preference-weighted) and one ignoring (equally weighted) domain preferences. To assess accuracy, the average proportion of judgment variance accounted for by each model was determined and both accounted for approximately 50%. However, for patients showing the greatest differences in importance across domains, the preference-weighted model was more accurate. Findings are discussed in the context of enhancing HRQOL assessment.