Survival and death causes of patients with giant cell arteritis in Western Norway 1972-2012: a retrospective cohort study.

BACKGROUND: Our objective was to determine the survival and causes of death in a large and well-characterized cohort of patients with giant cell arteritis (GCA). METHODS: This is a hospital-based, retrospective, observational cohort study including patients diagnosed with GCA in Western Norway during 1972-2012. Patients were identified through computerized hospital records using the International Classification of Diseases (ICD)-coding system. Medical records were reviewed. Patients were randomly assigned population controls matched on age, sex, and geography from the Central Population Registry of Norway (CPRN). Date and cause of death were obtained from the Norwegian Cause of Death Registry (NCoDR). The survival was analyzed using Kaplan-Meier methods with the Gehan-Breslow test and the causes of death using cumulative incidence and Cox models for competing risks. RESULTS: We identified 881 cases with a clinical diagnosis of GCA of which 792 fulfilled the American College of Rheumatology (ACR) 1990 classification criteria. Among those fulfilling the ACR criteria, 528 were also biopsy-verified. Cases were matched with 2577 population controls. A total of 490 (56%) GCA patients and 1517 (59%) controls died during the study period. We found no difference in the overall survival of GCA patients compared to controls, p = 0.413. The most frequent underlying causes of death in both groups were diseases of the circulatory system followed by cancer. GCA patients had increased risk of dying of circulatory disease (HR 1.31, 95% CI 1.13-1.51, p < 0.001) but lower risk of dying of cancer (HR 0.56, 95% CI 0.42-0.73, p < 0.001) compared to population controls. CONCLUSIONS: We found no difference in the overall survival of GCA patients compared to matched controls, but there were differences in the distribution of underlying death causes.

Correction to: Incidence of giant cell arteritis in Western Norway 1972-2012: a retrospective cohort study.

Following publication of the original article [1], the authors reported an error.

Incidence of giant cell arteritis in Western Norway 1972-2012: a retrospective cohort study.

BACKGROUND: Giant cell arteritis (GCA) is the most common systemic vasculitis in persons older than 50 years. The highest incidence rates of the disease have been reported in Scandinavian countries. Our objective was to determine the epidemiology of GCA in an expected high-incidence region during a 41-year period. METHODS: This is a hospital-based, retrospective, cohort study. Patients diagnosed with GCA in Bergen health area during 1972-2012 were identified through computerized hospital records (n = 1341). Clinical information was extracted from patients' medical journals, which were reviewed by a standardized method. We excluded patients if data were unavailable (n = 253), if the reviewing rheumatologist found GCA to be an implausible diagnosis (n = 207) or if the American College of Rheumatology (ACR) 1990 classification criteria for GCA were not fulfilled (n = 89). Descriptive methods were used to characterize the sample. Incidence was analyzed by graphical methods and Poisson regression. RESULTS: A total of 792 patients were included. The average annual cumulative incidence of GCA was 16.7 (95% CI 15.5-18.0) per 100,000 of the population ≥ 50 years old. The corresponding incidence for biopsy-verified GCA was 11.2 (95% CI 10.2-12.3). The annual cumulative incidence increased with time in the period 1972-1992 (relative risk (RR) 1.1, p < 0.001) but not in 1993-2012 (RR 1.0, p = 0.543). The incidence was higher in women compared to men (average annual incidence 37.7 (95% CI 35.8-39.6) vs. 14.3 (95% CI 13.2-15.5), p < 0.001) with women having a twofold to threefold higher incidence rate throughout the study period. Average annual incidence increased with age until the 7th decade of life in both sexes throughout the study period (2.8 (95% CI 2.3-3.3) for age <60, 15.5 (95% CI 14.4-16.8) for age 60-69, 34.5 (95% CI 32.8-36.4) for age 70-79 and 26.8 (95% CI 25.3-28.4) for age ≥80 years, p < 0.001 for all age adjustments). CONCLUSIONS: Our study confirms an incidence of GCA comparable to previous reports on Scandinavian populations. Our results show increasing incidence from 1972 through 1992, after which the incidence has levelled out.