Measuring pain in oral lichen planus: a comparative study of four assessment scales and their correlation

Oral lichen planus is a chronic disease of the oral mucosa, with pain as one of its main symptoms. This study aimed to assess the correlation between the results of four pain intensity measures-including the Visual Analog Scale (VAS), Numeric Rating Scale (NRS), Short Form McGill Pain Questionnaire (SF-MPQ), and Verbal Rating Scale (VRS)- in a population of patients diagnosed with oral lichen planus. In this prospective observational study, 66 patients with oral lichen planus participated. Four pain assessment scales were used, including VAS, NRS, VRS, and SF-MPQ. Participants completed these assessments at baseline and again after two weeks of treatment. A paired t-test, Spearman correlation, linear regression analysis, and adjusted multiple regression analysis (regarding age and level of education) were used to analyze the data. All four scales were sensitive to changes in pain after treatment and a significant reduction in pain scores was observed (p < 0.001). There was a strong positive correlation between all scales (p < 0.001). Regression analysis showed that scores on each scale could significantly predict scores on the other scales (p < 0.001). Multiple regression analysis adjusted for age and level of education, showed the correlations between the pain scales remained strong and significant (p < 0.001). These commonly used pain assessment scales showed strong correlation with each other, and it seems that the results obtained from each might be comparable with the others. However, further researches in larger studies and different populations are needed.