OBJECTIVES:   Following EuroQol EQ-5D valuation study protocol, Taiwan pilot study was just finished. The responses and quality control findings were obtained for quality improvement of interview. The aim of this study was to explore the other indicators to evaluate the QC and its potential associated factors in pilot study. METHODS:  In addition to evaluate the main QC criteria in EuroQol EQ-5D valuation study protocol, we intend to explore the other QC parameters and its potential factors in EQVT study in Taiwan. While interviewers were informed to demonstrate the 3 practice time-trade off (TTO) tasks, the corresponding final answers could be the reference to anchor and compare the logic of participants’ responses. Concerning Asian people tended to give up life in the worst health state, the responses toward the TTO final answers of the worst health status were compared and contrasted with that for the 3 practice TTO tasks. The associated factors of background questions using the descriptive analysis, independent ttests and appropriate bivariate analysis were also evaluated. RESULTS:  In the pilot study, 10 trained interviewers have completed 50 pilot interviews. 26% of them ever experienced severe illness, 62% had their family members experience severe illness and 46% chose to give up 20 out of 20 years in the worst health state. While the TTO final answers for the worst health state was strongly correlated with that of severe practice of TTO task (r=0.56), those who experienced with severe illness in caring for others and disagreed that “bad living better than good death” tended to give up more time than the counterparts (p_s<0.05). CONCLUSIONS:  The associations of TTO final answers between the worse health state and the practice severe task and the participants’ experience of severe illness and belief about “death” could be other potential factors to evaluate the quality of interview in EQ-VT study.