Prevalence of primary Sjogren's syndrome in Turkey: a population-based epidemiological study

The aim of this study was to determine the prevalence of primary Sjogren's syndrome (pSS) in a general Turkish population according to the latest proposed American-European Consensus Group (AECG) criteria and European-1 (EU-1) criteria. The study was conducted in two districts of Izmir and involved 2835 subjects 20 years of age and older. In the first stage, face-to-face interviews were performed at the registered households. In the second stage, subjects reporting symptoms of both dry eye and dry mouth were invited to the hospital for a full examination, which included Schirmer-1, sialometry and serologic tests. In the third stage, a minor salivary gland biopsy was performed as required. A total of 2887 subjects were contacted and a complete interview was obtained for 2835 (1551 female, 1284 male) subjects. A total of 159 subjects (126 female, 33 male) confirmed oral and ocular dryness, and 86 of these patients (54.1%) underwent a detailed clinical examination in the hospital. pSS was diagnosed in 10 patients (nine females) according to the EU-1 criteria, and in six patients (six females) according to the AECG criteria. We found a minimum crude prevalence of 0.21% [95% confidence interval (CI): 0.03-0.29] in the sample population and an age-sex adjusted prevalence of 0.16% (95% CI: 0.06-0.35), according to AECG criteria. According to EU-1 criteria, these prevalence rates were found to be 0.35% (95% CI: 0.10-0.45) and 0.28% (95% CI: 0.13-0.51) respectively. The pSS prevalence rates found in the Turkish population in this study were lower than the estimated prevalence rate in a general population.