Using the European Community (EC) criteria for classification Vitali et al. Arthritis Rheum 1993;36:340 7, we report the prevalence estimates of Sjogren's syndrome (SS) from a general population and present the first population data to assess the impact of the syndrome.
A cross-sectional population-based survey performed on 1000 adults, aged 18-75 yr, randomly selected from a population register. Responders to the initial postal phase were invited for an interview. The five criteria measured at interview were: (1) the reporting of subjective oral symptoms lasting for > 3 months; (2) the reporting of subjective ocular symptoms lasting for >3 months; (3) Schirmer-I test; (4) unstimulated salivary flow; (5) autoantibodies [Ro (SS-A), La (SS-B), rheumatoid factor (RF), antinuclear antibodies (ANA)]. SS was diagnosed if at least four of these five criteria were positive. The MOS Short-form 36 (SF-36), General Health Questionnaire (GHQ) and the Health and Fatigue Questionnaire (HFQ) were completed by subjects after the interview, and scores were compared between those with and without a diagnosis of SS.
A total of 341 subjects completed both the postal questionnaire and home visit. A diagnosis of SS could be given to 13 subjects. After adjusting for the presence of possible bias due to non-response, our best estimate of the prevalence of SS in the study population was 33 per 1000 subjects (95% CI 22 44). The prevalence of the disorder was higher in females (38; 95% CI 27-52) and for those subjects aged > or = 55 yr (46; 95% CI 34-61). Those subjects diagnosed positively were more impaired for each of the eight dimensions of the SF-36 than those without a diagnosis, and also suffered from higher levels of depression and fatigue.
SS affects approximately 3-4% of adults and in the general population appears to be associated with a clinically significant impairment of a subject's health and well-being.