To estimate the point prevalence of primary Sjögren's syndrome (pSS) in two populations, aged 40-44 and 71-74 years, using two sets of classification criteria.
The participating individuals were recruited from the Hordaland Health Study (HUSK) conducted during 1997-99. A total of 18 592 individuals born 1953-57 and 3346 individuals born 1925-27 were sent a questionnaire covering various health-related questions, including four questions about sicca symptoms. Among those answering positive to at least one of the four questions, 99 and 90 individuals born 1953-57 and 1925-27, respectively, were examined further. For diagnosis of pSS two classifications were used, the preliminary European criteria from 1993, and the revised European criteria from 1996.
By using the two classification criteria from 1993 and 1996, the point prevalences were 0.44% [95% confidence interval (CI) 0.34-0.57] and 0.22% (95% CI 0.15-0.32), respectively, for the population group born 1953-57. The corresponding estimates were 3.39% (95% CI 2.77-4.14) and 1.40% (95% CI 1.02-1.92) for the population born 1925-27.
The point prevalence of pSS was approximately seven times higher in the elderly population aged 71-74 years compared to individuals aged 40-44 years, regardless of the classification criteria used.