Developing an Australian Value Set for the Recovering Quality of Life-Utility Index Instrument Using Discrete Choice Experiment With Duration

Objectives The Recovering Quality of Life-Utility Index (ReQoL-UI) instrument was designed to measure the quality-of-life outcomes for people older than 16 years with mental health problems. We aimed to elicit societal preferences for the ReQoL-UI health states to facilitate better decision making in Australia. Methods A discrete choice experiment with duration was embedded in a self-completed online survey and administered to a representative sample (n = 1019) of the Australian adult population aged 18 years and older stratified by age, sex, and geographic location. A partial subset design discrete choice experiment was used with 3 fixed attributes and 5 varying attributes, containing 240 choice tasks that were divided into 20 blocks so that each respondent was assigned a block of 12 choice tasks. The value set was modeled using the conditional logit model with utility decrements directly anchored on the 0 to 1 dead-full health scale. Preference heterogeneity was tested using a mixed logit model. Results The final value set reflects the monotonic nature of the ReQoL-UI descriptive systems where the best health state defined by the descriptive system has a value of 1 and the worst state has a value of −0.585. The most important dimension was physical health problems, whereas the least important attribute was self-perception. Sensitivity and preference heterogeneity analyses revealed the stability of the value set. Conclusions The value set, which reflects the preferences of the Australian population, facilitates the calculation of an index for quality-adjusted life-years in mental health intervention cost-utility analyses.