Reliability and cross-cultural validity of a Japanese version of the Dental Fear Survey

BACKGROUND: This study established the reliability and cross-cultural validity of a Japanese version of the Dental Fear Survey (DFS). METHODS: Two studies were carried out in separate populations. The first involved 166 Japanese dental and nursing students and assessed internal consistency and test-retest reliability. The second involved 2,095 Japanese parents or guardians of school children and tested the hypothesis that the conceptual structure of the Japanese translation was consistent with the U.S. version using Structural Equation Modeling (SEM). RESULTS: In the first study Cronbach alpha ranged from .94 to .96 and test-retest reliability (Spearman correlation) ranged from .89 to .92. The intra-class correlation coefficients (ICC) was 0.919 (95%CI: 0.892 – 0.940). In the second study SEM was used on the covariance matrix of the 20 questions in a random sample of 600 questionnaires to evaluate the goodness of fit of the theoretical model; and then, in an exploratory manner corrected for specification errors until a model that fit the data well was achieved. CONCLUSION: The Japanese version of the DFS appears reliable and demonstrates cross-cultural validity. The modeling confirms the three factors on which the English language version was based.