Archives of medical research
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Comparative Study
Comparison of three rating scales for measuring subjective phenomena in clinical research. I. Use of experimentally controlled auditory stimuli.
An interest in measuring subjective phenomena such as pain, nausea, anxiety, etc. has led clinicians to develop three types of ratings: the visual analog scale (VAS); the verbal rating scale (VRS), and the numeric rating score (NRS). These ratings are regarded as global scales because they lack criteria to demarcate diverse dimensions or categories that comprise each scale. The purpose of this study was to evaluate validity and consistency of usage for these scales. Criterion for validity consisted of an experimentally controlled intensity for auditory stimuli. ⋯ The three instruments appeared reasonably accurate, with VAS having highest scores. VRS appeared sufficiently consistent to be regarded as providing reliable scientific information.