Reliability of Visual Analog and Verbal Descriptor Scales for "Objective" Measurement of Temporomandibular Disorder Pain

Abstract
Eight dentists viewed standardized videotapes showing palpations of the temporomandibular joint and muscles of mastication and recorded their judgments concerning the amount of pain the patient was experiencing. Judgments were recorded using a four-point verbal descriptor scale (VDS) ("none", "mild", "moderate", "severe "pain) or a 100-mm visual analog scale (VAS) anchored with the terms "no pain" and "worst pain possible". Test/re-test reliability over a one-week period and interjudge reliabilities were calculated for each scale; reliabilities of the two scales were directly compared based on the statistical equivalence of weighted kappa and the Intraclass Correlation Coefficient.