Utility and validity of a single-item visual analog scale for measuring dental anxiety in clinical practice

We evaluated whether a visual analog scale (VAS) was comparable to the multi-item Modified Dental Anxiety Scale (MDAS) in assessing dental anxiety in clinical practice. In total, 200 consecutive patients aged 20-70 years who presented at the dental outpatient department of SRM Dental College, Chennai were enrolled. The test-retest value for the VAS was 0.968. The Spearman rank correlations between the VAS and MDAS items and total score were significant (P < 0.001). The Spearman rank correlation between postponement of a dental visit and the VAS also showed a strong correlation (r = 0.473, P < 0.001). On linear regression analysis, the coefficient of determination showed a strong relationship between the two variables; the MDAS accounted for 74% of the variation. The regression coefficient was statistically significant (P < 0.001). On the basis of receiver-operating-characteristic curve analysis, a VAS cut-off value of ≥4.8 was selected to discriminate between patients who were and were not anxious, and a cut-off value of ≥7 was selected to identify patients with dental phobia. The weighted kappa was 69% for agreement between MDAS and the VAS in identifying patients with and without dental anxiety at cut-offs of 13 and 4.75, respectively. The VAS was found to be a valid measure and was comparable to the multi-item MDAS.