Representation of verbal pain descriptors on a visual analogue scale by dental patients and dental students

Verbal rating scales (VRS), composed of ranked pain descriptors, are often employed in pain research. Factors that may influence the subjective pain intensity values, however, are not well established. In this study, 5 common pain descriptor adjectives were represented on a visual analogue scale (VAS) by a group of 80 dental students, by a group of 48 patients undergoing periodontal therapy, and by a group of 31 dental phobic patients. It was thought that each group of individuals on conducting the test represented a different degree of apprehension, ranging from a relaxed to a very tense status. There were differences in the interpretation of the pain descriptors between groups. Furthermore, age seemed to influence the interpretation of the pain descriptors. No correlation was found with gender. The descriptors did not divide the analogue scale into equal segments. 71% of all subjects gave the adjective "mild" a lower pain intensity representation than the adjective "weak", while the order was reversed among remaining subjects. Findings cast doubt on the reliability of VRS and the data handling methods commonly adopted in clinical pain research.