FRI0518 Incidence, characteristics and management of giant cell arteritis in france: a study based on national health insurance claims data

Abstract

Background/Purpose: Giant cell arteritis (GCA) is an immune-mediated, primary systemic vasculitis that affects large and medium-sized arteries. GCA may cause vision loss in up to 20% and requires long term glucocorticoids (GCs). There are currently few data available in France on the epidemiology, patients' (pts) characteristics, diagnosis and management of GCA in a real-world setting. The objectives of this study were to address these questions using Health insurance claims data. Method(s): This retrospective cohort study used the EGB (Echantillon Generaliste des Beneficiaires) database, a 1% random and representative sample of the French national Health insurance system. The EGB database contains anonymous demographic and comprehensive medical data on conditions with long-term disease (LTD) status, hospitalizations and reimbursement claims for medications dispensed in the community. The study used data collected between Jan 1, 2007 and Dec 31, 2015. Inclusion criteria were: 1) age >=50 years; 2) hospitalization for GCA or LTD status for GCA (ICD-10 codes: M31.5/6); and 3) >=4 drug dispensing of oral GCs within 6 months around the index date. The index date was defined as the date of 1st occurrence of GCA code and cases were considered as incident if the GCA code first occurred after >=2 years of follow-up. Demographics, co-morbidities, diagnostic tests and therapies were analysed. A treatment sequence was defined as the start of a new drug or the resumption of the same drug after a stop >=3 months. Prevalence and annual incidence were calculated by using the people recorded in the database as denominator. Result(s): Among the 752717 people recorded in the EGB, 241 pts fulfilled our criteria. Prevalence was 150/100000 people >=50 years-old. Around 24 pts were newly diagnosed/year with an annual incidence of 7-10/100000 people >=50 years-old. 72% of the 241 pts were females, mean age was 77.5 (+/-8.9) and mean follow-up 3.7 (+/-2.6) years. In the 12 months before index date, 74.3% of the pts had >=1 proxy for hypertension, 39.4% for depression/insomnia and 33.6% for osteoporosis. After index date, temporal artery biopsy (TAB) was performed in 43.2%, high-resolution Doppler ultrasound of the temporal arteries in 35.3% and 18FDG-PET in 11.6%. Among the 235 pts (97.5%) who had >=1 drug dispensing of oral GCs, 198 pts (84.3%) used only GCs while 37 (15.7%) also received 1 to 3 adjunctive agents. Mean 1st GCs sequence duration was 17.2 months (+/-16.5) in 96.6%. 95 pts (40.4%) had a 2nd sequence, i.e. resume GCs and or start a new drug for a duration of 6.7 months (+/-8.1) for GCS alone or 12.2 months (+/-8.8) for GCs + adjunctive drug. The most commonly prescribed adjunctive agent was MTX (12.0%). Use of other adjunctive drugs was marginal: hydroxychloroquine 7 pts, azathioprine 4, cyclophosphamide 1, infliximab 1, adalimumab 2 and etanercept 1 pt. Conclusion(s): These real-world data indicate an incidence of GCA in France of 7-10/100,000 people >=50 years-old and underline that most patients with GCA are treated with GCs alone whereas adjunctive agents, mainly methotrexate, are given to 15% of patients. The utilization of TAB in only half of the patients might reflect a shift towards increasing use of imaging techniques to diagnose GCA.