P2-146 Epidemiological and clinical characteristics of BehÇet's disease in Japan, by years after disease onset, using a clinical database on patients receiving financial aid for treatment

Objective Behcet9s disease is an autoimmune disease with multisystem vasculitis. The objective of this study was to explore the natural history of Behcet9s disease after onset, using a clinical database on patients receiving financial aid for treatment. Methods In the fiscal year 2005, 16 627 patients with Behcet9s disease were registered to receive public financial aid from the Ministry of Health, Labour and Welfare (MHLW) in Japan. The MHLW has an on-line registration system of intractable diseases including Behcet9s disease. We obtained the 2005 clinical database, which contained 9416 patients with Behcet9s disease. We confirmed the distribution of years from disease onset, and calculated duration from onset to the first doctor9s visit. We analysed changes in disease severity, and prevalence of the types of Behcet9s disease, according to years after disease onset. Results The proportion of years from disease onset of less than 1 year was 9%, 2–5 years was 15%, 6–15 years was 30%, and more than 16 years was 46%. The average duration from onset to the first doctor9s visit was about 2.5–3 years. Prevalence of the complete type of Behcet9s disease increased with the years after disease onset. Regarding disease severity, the proportion of severe cases increased with the years from disease onset. Conclusion Using a clinical database with Behcet9s disease, we characterised the clinical/epidemiological features of Behcet9s disease according to years after disease onset.