Meaningful improvement thresholds in measures of pain and quality of life in oral lichen planus.

Objectives To evaluate the responsiveness of measures of pain and oral health-related quality of life (OH-QoL) in patients with oral lichen planus (OLP) and to determine thresholds for minimal important change (MIC) and minimal important difference (MID) for use in this patient population. Methods Data from baseline and 4-month follow-up including Visual Analog Scale (VAS), Numerical Rating Scale (NRS), 14-item Oral Health Impact Profile (OHIP-14), 15-item and 26-item Chronic Oral Mucosal Disease Questionnaire (COMDQ-15; COMDQ-26) were collected from 157 patients with OLP. Responsiveness was assessed by testing hypotheses and calculating the area under the curve. MIC and MID were established based on triangulation of distribution-based and anchor-based estimates. Results The results supported adequate responsiveness of VAS, NRS, COMDQ-15 and COMDQ-26 for use in OLP, while the OHIP-14 demonstrated relatively low sensitivity to detect improvement in the OLP status. Recommended meaningful improvement thresholds were as follows: VAS (MIC 16 mm; MID 18 mm), NRS (MIC/MID 2 points), OHIP-14 (MIC/MID 5 points), COMDQ-15 (MIC 5 points; MID 6 points) and COMDQ-26 (MIC/MID 9 points). Conclusion This study provides some evidence of responsiveness as well as establishing meaningful improvement thresholds in scores of pain and OH-QoL measures in OLP.