Background Giant cell arteritis is the most common vasculitis in the western world in those aged greater than 50yrs old and has significant morbidity from both its pathology and treatment. There are no recent (after 2001) estimates of the occurrence in the UK.
Objectives The aim of this study was to estimate the occurrence of GCA in the UK and to record death from all cause mortality upto a period of ten years post diagnosis.
Methods All histology reports for patients referred to a university hospital in Norwich, Norfolk for temporal artery biopsy between 1st January 2003 and December 2009 were reviewed. The population denominator was calculated from national census data to calculate incidence. All positive biopsy proven patients with GCA were followed until 7th January 2013. Patients were followed from time of diagnosis until either their death or 7th January, 2013.
Results There were 325 temporal biopsies performed at the NNUH between the years 2003 to 2009. Subsequently 119 individuals were diagnosed with biopsy positive GCA (36.6%). The mean age at diagnosis was 75.6yrs. 85 were women (71.4%). The incidence rate per 100,000 was 6.8 (95% CI = 4.2 to 11.1) in people aged >50years. By 7th January, 2013, 25 patients (21.0%) with biopsy confirmed GCA had died with a median follow up of 66 months (44-86). One, 2 and 5 year survival rates were 96, 92, and 84%, respectively. There were no statistical significant survival gender effects (male vs female p=0.308).
Conclusions The results reveal an estimate of 6.8 per 100,000 people aged >50yrs. This is much lower than the estimate from the General Practice Research Database (GPRD) study carried out in 2001. Within the GPRD study only three out of a selection of 45 cases that were reviewed had a positive temporal artery biopsy (6.7%) and 10 cases (22.2%) were diagnosed and managed in primary care alone. Assuming an incidence for our study is similar to that of the GPRD then in Norfolk perhaps as much as 50% of cases of GCA are managed in the community without undergoing biopsy. However death from all cause mortality does not appear to be too dissimilar compared to the general population.
References Smeeth L, Cook C, Hall AJ. Incidence of diagnosed polymyalgia rheumatica and temporal arteritis in the United Kingdom, 1990-2001. Annals of the Rheumatic Diseases. 2006 Aug;65(8):1093-8.
Disclosure of Interest None Declared