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.

Methods: This retrospective cohort study used the EGB (Echantillon Généraliste des Bénéficiaires) 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 1^st 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.

Results: 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 1^st GCs sequence duration was 17.2 months (±16.5) in 96.6%. 95 pts (40.4%) had a 2^nd 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: 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.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/incidence-characteristics-and-management-of-giant-cell-arteritis-in-france-a-study-based-on-national-health-insurance-claims-data/