Japanese health utilities index mark 3 (HUI3): measurement properties in a community sample

BACKGROUND: The McMaster Health Utilities Index Mark 3 (HUI3) is a generic multi-attribute, preference-based system for assessing health-related quality of life (HRQOL). This study describes the translation procedures and cultural adaptation of the Japanese HUI3 and its measurement properties in a community sample. METHODS: The Japanese HUI3 was developed through forward and back translations in cooperation with the developers of the HUI. Acceptability, comprehensibility of questionnaires, and test-retest reliability were assessed. In a community survey of a total of 3860 people (age: 41 ± 14.3, male/female: 2651/1209), the Canadian scoring function was used to calculate utility scores. Construct validity was assessed by examining the relationship between 20 personal characteristics and utility scores. RESULTS: Linear regression estimates demonstrated a significant negative relation between HUI3 utility score and low education, male gender, poor interpersonal relationships, older age, and a higher number of chronic diseases. Single-attribute utility scores were associated with chronic conditions in the manner expected. The community samples were relatively healthy. More than 90% of the respondents were distributed in levels 1 and 2 in all attributes except cognition. Interpretability of utility score was assessed by estimation of the relationship between visual analogue scale (VAS) and the self-rated health and utility score. Independence of attributes was assessed. For only 3 of the 28 possible cross-comparisons among the 8 attributes were correlations coefficients greater than 0.25. CONCLUSION: Translation and adaptation of the HUI3 questionnaire into Japanese was successful, but the sample size and selection bias limit the interpretation of our study conclusions.