Systematic Review and Meta-Analysis of Giant Cell Arteritis

Giant cell arteritis (GCA) is a serious systemic vasculitis that can lead to irreversible complications, if not promptly recognized and treated. Global estimates of GCA incidence and prevalence show considerable variation, reflecting differences in diagnostic criteria, geographic context, and evolving clinical practices. This study updates prior meta-analyses of GCA epidemiology, which predate widespread use of contemporary diagnostic approaches. The objective was to systematically review and meta-analyze population-based studies reporting GCA incidence and prevalence worldwide and explore sources of heterogeneity.

A systematic search of PubMed, MEDLINE, Embase, and Scopus was performed from inception to October 2025. Studies were included if they reported population-based incidence or prevalence of GCA in adults ≥50 years. Random-effects meta-analyses were performed using the restricted maximum likelihood estimator for τ², and meta-regressions were used to explore potential sources of heterogeneity.

A total of 5,465 records were screened, and 54 studies from 23 countries were included. Pooled crude annual incidence was 10.59 per 100,000 persons ≥50 years (95% confidence interval [CI] 7.69-13.48; I² = 99.89%, τ² = 67.33, Q (31) = 16,434.60; P < 0.001), whereas pooled prevalence was 67.68 per 100,000 persons ≥50 years (95% CI 34.15-101.20; I² = 99.97%). Incidence increased with absolute latitude. The number of case-ascertainment methods and data sources showed no association.

The highest incidence estimates came from Northern Europe and the highest prevalence estimates from North America. Pooled incidence was approximately two-fold higher in female patients.