Abstract
BACKGROUND: Comprehensive epidemiological and geoepidemiological data on sarcoidosis in Japan, particularly including mild cases, remains limited. This study investigated the prevalence, cumulative incidence, and clinical characteristics of sarcoidosis using large-scale claims data. METHODS: This retrospective study analyzed data from the Deidentified Scrubbed Claims Healthcare Database (DeSC), covering approximately 20 million individuals in Japan. We investigated patients diagnosed with sarcoidosis between April 2014 and October 2023. The prevalence and cumulative incidence were calculated for fiscal year 2021 (FY2021), and patient characteristics, including comorbidities and treatments, were analyzed. RESULTS: In FY2021, the estimated prevalence and cumulative incidence of sarcoidosis were 73 and 9.0 per 100,000, respectively. Among 10,910 cases analyzed for clinical characteristics, 68.8% were female individuals, with a mean age of 69.7 years for female individuals and 62.6 years for male individuals. No clear regional differences were observed in prevalence or cumulative incidence (not tested). Oral corticosteroids were prescribed to 25.2% of patients, with a median annual dose of 1,645 mg. Other systemic treatments were prescribed to <3% of patients. The common comorbidities included type 2 diabetes mellitus (21.6-50.0%), sleep disorders (25.1-36.0%), and fractures (8.2%). Sarcoidosis was also associated with other autoimmune diseases, including rheumatoid arthritis, Sjögren syndrome, and autoimmune thyroiditis. CONCLUSION: The results of this study provide new insights into sarcoidosis epidemiology and clinical characteristics in Japan, including treatment patterns and comorbidities. These findings suggest potential shared immunological mechanisms among various autoimmune diseases and highlight the need for comprehensive management approaches that consider both disease-specific and treatment-related complications. This article was previously presented as a meeting abstract at the 65th Annual Meeting of The Japan Respiratory Society on April 12, 2025.