The Recovering Quality of Life-Utility Index (ReQoL-UI) instrument was designed to measure the quality of life outcomes for people over 16 years of age with mental health problems. We aim to elicit societal preferences for the ReQoL-UI health states to facilitate better decision-making in Australia. A discrete choice experiment (DCE) with duration was embedded in a self-complete online survey and administered to a representative sample (n=1019) of the Australian adult population aged 18 years and more, stratified for age, sex and geographic location. A partial subset design DCE was used with 3 fixed attributes and 5 varying attributes containing 240 choice tasks that were blocked into 20 blocks, so that each respondent was assigned a block of 12 choice tasks. The value set was modelled using the conditional logit model with utility decrements directly anchored on the 0 to 1 dead-full health scale. Preference heterogeneity was tested using the mixed logit model. 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 while the least important attribute was self-perception. Sensitivity analysis and analysis of preference heterogeneity show the stability of the value set. 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 interventions cost-utility analyses.
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