Methods for Measuring Temporary Health States for Cost-Utility Analyses

A variety of methods are available to measure preferences for temporary health states for cost-utility analyses. The objectives of this review were to summarize the available temporary health-state valuation methods, identify advantages and disadvantages of each, and identify areas for future research. We describe the key aspects of each method and summarize advantages and disadvantages of each method in terms of consistency with QALY theory, relevance to temporary health-state-specific domains, ease of use, time preference, and performance in validation studies. Two broad categories of methods were identified: traditional and adapted. Traditional methods were health status instruments, time trade-off (TTO), and the standard gamble (SG). Methods adapted specifically for temporary health-state valuation were TTO with specified duration of the health state, TTO with a lifespan modification, waiting trade-off, chained approaches for TTO and SG, and sleep trade-off. Advantages and disadvantages vary by method and no 'gold standard' method emerged. Selection of a method to value temporary health states will depend on the relative importance of the following considerations: ability to accurately capture the unique characteristics of the temporary health state, level of respondent burden and cognition, theoretical consistency of elicited preference values with the overall purpose of the study, and resources available for study development and data collection. Further research should focus on evaluating validity, reliability and feasibility of temporary health-state valuation methods.