LAUSR

The Euro-Qol group introduced the EQ-5D-5L descriptive system in 2009 [1], with the first publication describing the tool appearing in 2011 [2]. This revised version of the EQ5D instrument introduced five response levels, alongside changes to the wording used to describe responses in the mobility domain. The five-level version of the EQ-5D descriptive system was developed in response to perceived failings of the three response-level EQ-5D-3L, notably in its sensitivity to changes in health [3], but also ceiling effects [2] and an ‘uneven’ distribution of responses as measured by the valuation tariff [4]. The first UK valuation study of the 5L descriptive system was formally available in 2017 [4]. As Brazier, Bryan and Briggs recently summarize [5], the 5L version of the instrument has been found to reduce ceiling effects and exhibits a more even distribution of responses. Hernandez et al. [6] have shown that as a consequence of the changes to the tool and the new valuation system, utility scores derived using the 5L version are compressed towards the full-health end of the measurement scale, suggesting that while the 5L version describes more distinct health states, the values placed on them are potentially less sensitive for detecting clinically meaningful changes in health utility. Given the existing 3L and 5L valuation tariffs, costeffectiveness analyses using different versions of the tool are likely to lead to different results and possibly different decisions on the cost effectiveness of interventions.