OBJECTIVE: Our objective was to develop a value set based on Irish utility values for the EuroQol 5-Dimension, 5-Level instrument (EQ-5D-5L).
METHODS: The research design and data collection followed a protocol developed by the EuroQol Group. The EuroQol Valuation Technology (EQ-VT) software was administered using computer-assisted personal interviews to a representative sample of adults resident in Ireland between 2015 and 2016. Utility values were elicited using two stated-preference techniques: time trade-off (TTO) and discrete-choice experiment (DCE). Each respondent completed a valuation exercise in which the EQ-VT system randomly selected one block of ten TTO questions from ten blocks relating to a possible 86 health states. One block of seven DCE pairs from 28 blocks of a possible 196 pairs of health states were randomly selected to accompany this. The relationship between utility values and health states was analysed using a hybrid regression model that combined data from the TTO and DCE techniques and expressed these as a function of the health state presented to the individual. This model estimated coefficients for 20 dummy variables that characterised each health state in the EQ-5D-5L framework, with the lowest level of severity providing the reference category in each domain. The relationship between weighted and unweighted TTO and DCE analyses of main effects was analysed separately.
RESULTS: Comparison of weighted and unweighted models revealed no substantive differences in results with respect to either DCE or TTO models. The unweighted hybrid model produced estimated effects, the ordering of which was intuitively consistent within each domain: lower levels of health were associated with lower utility values. Differences were evident between domains with respect to valuations; the disutility associated with conditions related to anxiety/depression and pain/discomfort was higher than for other domains. The decrement in utility associated with movement from the highest to the lowest level of health was 0.344 for mobility, 0.287 for self-care, 0.187 for usual activities, 0.510 for pain/discomfort and 0.646 for anxiety/depression.
DISCUSSION: The results present the first value set based on the EQ-5D-5L framework for a representative sample of residents in Ireland. The set reveals a higher decrement in utility associated with anxiety/depression than with other domains of health. Caution is warranted in comparisons with other value sets. That said, those in England, the Netherlands, Uruguay and China reveal that, whereas Irish values are broadly consistent with respect to mobility, self-care and usual activities, residents of Ireland attach a higher decrement to pain/discomfort and anxiety/depression than do other populations.