Does context matter? A discrete choice experiment investigating the impact of palliative context on EQ-5D-5L health state valuation.

Purpose: Ensuring the values applied in health technology assessment of palliative care accurately reflect the palliative context is crucial for informed and effective resource allocation. The aim of this study is to examine whether the valuation of EQ-5D health states varies when framed within a palliative care needs context: limited life expectancy and availability of supports.

Methods: This study was a multinational cross-sectional discrete choice experiment (DCE) with respondents from the general populations of Australia (n = 2,082), Ireland (n = 1,280), and the UK (n = 2,009). Each participant was presented with a series of 20 choice sets, in which they were asked to choose between two EQ-5D-5L health states and immediate death. Half of the choice sets were accompanied by a "context vignette" while the remaining half were "context-free". The context vignettes, developed through a four-stage iterative process, described four distinct levels of palliative care needs. A D-efficient DCE design was developed, and the data were analysed using multinomial logit regression models.

Results: The study found inconsistencies in the EQ-5D-5L health state valuations in palliative contexts compared with context free valuation. Both life expectancy and level of support impacted health state valuation, with life expectancy having the larger effect. The inclusion of the palliative care vignettes substantially increased the number of health states that were given values worse than dead. This increase was more pronounced in Australia and the UK than in Ireland.

Conclusion: These results imply that EQ-5D value sets that are context free require careful interpretation, especially when applied in settings such as palliative care.