Validity, reliability and optimisation of the TOPICOP questionnaire for oral lichen planus.

Due to their anti-inflammatory and immunosuppressive effects, topical corticosteroids (TCs) are commonly used for the treatment of patients with oral lichen planus (OLP) with an erosive or ulcerative component. It has been suggested that many of these patients may suffer from fear or anxiety as a result of prolonged treatment with TCs. The objective of this study was twofold: (1) to optimise a patient reported outcome measure (PROM) in order to explore this feature, and (2) to evaluate this PROM in the treatment of OLP patients. A group of qualitative researchers adapted the TOPICOP questionnaire in order for it to be used as a PROM for OLP structural equation modelling (SEM) and internal consistency (IC) analysis. Consequently, 34 patients with symptomatic OLP who were undergoing treatment with TCs completed a questionnaire and underwent a clinical assessment. SEM presented an adequate fit (RMSA = 0.07, CFI = 0.94 and WRMR = 1.18), as well as a high IC (α = 0.81). A total of 16 patients (47.1%) reported TCs phobia. The receiver operating characteristic analysis (ROC) revealed that a TOPICOP value ≥50% predicted the presence of TCs phobia with a sensitivity of 93% and a specificity of 100%. The optimised TOPICOP scale proved valuable as a PROM in OLP. TCs phobia can be a real consideration in OLP, nonetheless, it does not appear to be an impediment to treatment adherence.