Whole‐Country and Regional Incidences of Giant Cell Arteritis in French Continental and Overseas Territories: A 7‐Year Nationwide Database Analysis

Abstract

Objective The incidence rate of giant cell arteritis (GCA) is poorly studied in France. Therefore, we conducted a national hospital database study to assess the overall and regional incidence rates of GCA in France, including overseas territories. Methods Through the national hospitalization database of all patients hospitalized in France, new incidental GCA was identified using International Classification of Diseases, 10th Revision medical codes (M31.5 = GCA; M31.6 = GCA and polymyalgia rheumatica [PMR]) during 2013‐2019. The regional incidences were analyzed by graphical methods and Poisson regression. Results A total of 16,540 new GCA with or without PMR diagnoses were identified in all French hospitals over 7 years. The female/male ratio was 1.8. The crude annual incidence rate of GCA with or without PMR was 9.64 (9.50‐9.79) per 100,000 persons aged 50 years or older in continental France and 2.91 (2.35‐3.47) in overseas areas. The GCA with or without PMR incidence rate regularly increased with age in both sexes but with a later peak in men (85 vs 80 years in women). The crude incidence rate was 11.43 (11.21‐11.65) in women and 7.50 (7.31‐7.70) in men. An east–western gradient was noted with an increasing standardized incident rate (SIR) from east to west (P < 10−3) using a departmental stratification of incident rates. Of note, all SIRs in continental regions were higher than those in overseas areas. Conclusion This French nationwide study provides new and dynamic insights regarding GCA with or without PMR incident rates at the country and regional levels. Important rate differences were observed between continental France and the overseas areas.