PURPOSE: There are 2 versions of EQ-5D, each with an associated valuation set: the 3-level version (3L) and the newer 5-level version (5L). NICE’s methods guide says that the 3L valuation set should be used ‘until an acceptable valuation set for 5L is available’. A 5L valuation set for England has recently been produced. However, the two instruments have different characteristics, and for most technologies the 5L gives a higher incremental cost-utility ratio than the 3L (using the UK valuation sets). This is a fast-moving field; by November we anticipate that NICE will have published an interim position statement on the 5L valuation set. Through its Decision Support Unit, NICE has commissioned work to examine the sources of differences between instruments and quality-assure the 5L. The EuroQol Foundation has also funded research into these issues and established a Taskforce to examine differences between 3L and 5L. The workshop will provide an overview of these developments and explore the implications for different stakeholders, including issues of relevance for those outside the UK. DESCRIPTION: Rosie Lovett will explain NICE’s interim position on the 5L valuation set and the rationale behind it, and provide guidance for company submissions. The workshop will then discuss the research that informed NICE’s interim position, along with work relevant to a longer-term position and the use of 5L more broadly. Allan Wailoo will present the Decision Support Unit’s work comparing 3L and 5L, including cost-effectiveness case studies from past NICE appraisals. He will explain methods for linking 3L and 5L, both descriptive systems and utilities, to allow all evidence to be incorporated into technology assessment. Nancy Devlin, representing the EuroQol Research Foundation, will discuss why the 5L was developed, the evidence for its advantages over 3L, and ongoing research into the characteristics of the valuation sets.