OBJECTIVES: Tinnitus is a common, chronic health-condition affecting 10% to 20% of the adult population and especially hearing impaired individuals. There is no curative therapy for this condition and treatment is aimed at increasing well-being. Measurement of health state utilities is an essential element of CEA in health care. Several studies found that different utility instruments provide different estimates of the same person’s level of utility. This study aims to gain insight into differences between utility measures, by determining the construct validity of EQ-5D and HUI3 and agreement between both measures in tinnitus patients. METHODS: Baseline data on EQ-5D and HUI3 of 159 patients in a randomized controlled clinical trial investigating cost-effectiveness of usual care versus specialized care of tinnitus, were examined. Agreement was assessed using the intra-class correlation coefficient (ICC). In absence of a gold standard to measure health state utility, construct validity was determined by comparing utility scores for clinical different groups, based on scores from the Tinnitus Questionnaire. RESULTS: Mean utility scores for EQ-5D (0.78; sd 0.20) and HUI3 (0.64; sd 0.27) were different (Wilcoxon Signed Ranks Test, P-value <0,001), agreement was low to moderate (ICC=0.40). EQ-5D and HUI3 showed a large correlation (Kendall’s Tau >0.50) between the dimensions: mobility (EQ-5D) and ambulation (HUI3), anxiety/depression (EQ-5D) and emotion level (HUI3), and pain/complaints (EQ-5D) and pain (HUI3). Both utility measures discriminated between clinically different groups. Groups with more severe tinnitus had lower utility scores (Kruskal-Wallis χ2=8.4, p=0.015 and χ2=26.9, p<.001 for EQ-5D and HUI3 respectively). CONCLUSIONS: This study shows that different utility measures lead to different utility scores among tinnitus patients. However, both measures are capable of discriminating between clinically different groups. Further research is conducted to show responsiveness of both measures to decide which is preferred in a tinnitus population. Results will be presented at the conference.