Equivalence of the original and revised dental anxiety scales.

Purpose: The Corah Dental Anxiety Scale (DAS) was introduced in 1969 as a brief, valid, and reliable instrument to measure anxiety about dental visits. Since then, changes in language usage and dental practice have rendered the scale outdated. In 1994, Ronis introduced the Dental Anxiety Scale-Revised (DAS-R), a version of the DAS revised to acknowledge the roles of dental hygienists and female dentists in the dental office. The current study was conducted to determine whether the original and revised scales are equivalent.
Methods: The study tested the equivalence of the two scales by including both in a questionnaire filled out by 141 male and female college students. Psychometric equivalence was examined by comparing the means, and reliabilities (alphas) of the two scales and by correlating the two scales with each other.
Results: Mean scores, variances, and reliabilities of the two versions of the scale did not differ. The Pearson correlation between the two scales was .98.
Conclusions: It appears that the DAS-R is psychometrically equivalent to the DAS and can be used in its place whenever more up-to-date wording is desired.