Time trend in the prevalence of oral lichen planus based on Taiwanese National Health Insurance Research Database 1996-2013

Background/Purpose: Oral lichen planus (OLP) is a common chronic inflammatory disease characterized by a T cell-mediated immune response against epithelial cells. The epidemiological survey of OLP in Taiwanese population was scarce. In this study, we investigated the time trend of prevalence stratified by gender, age, urbanization, and income of OLP based on National Health Insurance Research Database (NHIRD). Materials and methods: We studied the claims data of Taiwanese population from NHIRD 1996 to 2013. Patients with the diagnosis of OLP based on the International Classification of Diseases, Ninth Clinical Modification (ICD-9-CM) code: 697.0 were recruited in this study. Demographic characteristics were analyzed by multi-variate Poisson regression. Results: The prevalence of OLP increased significantly from 1.3 (per 10(5)) in 1996 to 12.8 (per 10(5)) in 2013 (p for trend < 0.001). The prevalence was higher among female than male (RR: 2.13; 95% CI: 2.07-2.18, p < 0.001). The subjects living in suburban area had a lower risk of OLP than those living in urban area (RR: 0.80; 95% CI: 0.78-0.82, p < 0.001). The higher income group had higher risk of OLP compared with the lower income group (RR, 2.27; 95% CI, 2.17 -2.36, p < 0.001). Conclusion: The prevalence of OLP in Taiwan significantly increased over the past 18 years. The mean age with OLP was shown in an increased pattern. In addition, OLP occurs more frequently in women than in men. (C) 2018 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.