Comparison between the Visual Analog Scale and the Numerical Rating Scale in the perception of esthetics and pain

Abstract

Background: Pain is an unpleasant, emotional, and sensorial experience. Esthetics and pain express perceptions or sensations that are subjective and personal, but non-consensual, between professionals and patients. The Visual Analog Scale (VAS) and the Numerical Rating Scale (NRS) are simple methods to evaluate such subjective phenomena.

Objective: To verify whether a concordance exists between VAS and NS in the perception of esthetics and pain.

Material and methods: Regarding esthetics, an on-line questionnaire was prepared with extra- and intra-oral images (adapted). The order of the scales was alternated between interwoven and sequential. Regarding perception of pain, respondents personally classified its intensity at the present moment, or over the past 30 days.

Results: A statistically significant concordance (P<0.001) - positive and moderate - was found between the scales, for the evaluation of both the extra- and intra-oral images, r=0.678 and 0.638, respectively. Regarding pain perception, taking formal education into account, no concordance was found between the two scales for participants who had "no formal education" (P>0.05). The concordance between the scales increased proportionally with the level of education.

Conclusion: There was a concordance between the scales with regard to esthetical perception and the evaluation of pain. When assessing esthetics, the order in which the two scales are applied does not affect the concordance between them. However, the strength of the concordance is influenced. Esthetic perception is not influenced by the differences between the panels of evaluators. The concordance between the two scales, for the evaluation of pain, increases proportionally with the level of formal education.

Keywords: Esthetic perception; Numerical Rating Scale; Pain; Pain measurement; Visual Analog Scale.