Background: The SF-6D and EQ-5D are widely used generic index measures as health-related quality of life. We assessed within-subject agreement between SF-6D and EQ-5D utilities with different preference weights, and their validities in measuring Chinese rural residents, before and after standardization scores.
Methodology/principal findings: Rural residents over 18 years old were interviewed using EQ-5D and SF-6D in Jiangsu Province, China. EQ-5D utility-scoring algorithms were used from three conversion tables from the United Kingdom, Japan, and the United States. Validities, Sensitivity and agreement between instruments were computed and compared. Factors affecting utility difference were explored with multiple liner regression models. Scores with standardization intervals of 0-1 in the two instruments were analyzed by the use of the above methods again. In 929 respondents, relative efficiency statistic and receiver operating characteristic curves analysis showed SF-6D to be the more efficient, followed by the EQ-5D model in Japan weights. Bland-Altman plot analysis showed paired SF-6D/EQ-5D in UK weights had better agreement. Though some risk factors were found, multiple liner regression demonstrated most coefficients were weaker than 0.2, and all R(2) values were less than 0.06. Standardization did not significantly influence these results except scores' value.
Conclusions/significance: SF-6D and next EQ-5D in Japan weights could be used for Chinese rural residents. Further research with larger sample size of population is needed to establish and determine the feasibility of standardization score.