Incidence, Prevalence, and Survival of Biopsy-Proven Giant Cell Arteritis in Northern Italy During a 26-Year Period

Objective. To investigate the epidemiology and mortality in patients with biopsy-proven giant cell arteritis (GCA) in northern Italy. Methods. All patients with incident temporal-artery biopsy-positive GCA, diagnosed between 1986 and 2012 and living in the Reggio Emilia area, were identified by using a pathology register and by reviewing all histopathologic specimens. For each patient, we identified 1 comparison subject from the same geographic area, matched for age and sex. Mortality rates and specific causes of death were reported. Results. There were 285 incident cases of biopsy-proven GCA (210 women) during the 26-year study period. The overall age- and sex-adjusted incidence per 100,000 persons ages >= 50 years was 5.8 (95% confidence interval [95% CI] 5.1, 6.5). Incidence was significantly higher in women (7.8 [95% CI 6.7, 8.9]) than in men (3.3 [95% CI 2.6, 4.1]) (P<0.0001). Annual age- and sex-adjusted incidence rates significantly increased by 15.9% per 3 years from 1986 to 2000, then significantly fell by -4.8% per 3 years from 2001-2012. The prevalence of GCA on December 31, 2012 was 87.9 (95% CI 75.8, 101.4). No significant differences in the mortality rates were observed between GCA patients (4.9 per 100 person-years [95% CI 4.1, 5.8]) and non-GCA subjects (5.6 [95% CI 4.7, 6.6]). No significant differences in causes of death were observed comparing GCA patients to non-GCA subjects. Conclusion. This large population-based study of biopsy-proven GCA confirmed the lower incidence of GCA in Mediterranean countries and did not observe any increased mortality risk.