Prevalence of Primary Sjögren's Syndrome in a US Population‐Based Cohort

Abstract

Objective To report the point prevalence of primary Sjögren’s syndrome (pSS) in the first population-based study performed in the United States. Methods Cases of all potential pSS patients living in Olmsted County, Minnesota on January 1, 2015 were retrieved using the Rochester Epidemiology Project resources, and ascertained by manual medical record review. pSS cases were defined according to physician diagnosis. The use of diagnostic tests was assessed and the performance of classification criteria was evaluated. The number of prevalent cases in 2015 was also projected based on 1976–2005 incidence data from the same source population. Results A total of 106 patients with pSS were included in the study: 86% were female, with a mean (SD) age of 64.6 (15.2) years and disease duration of 10.5 (8.4) years. A majority were anti-SSA positive (75%) and/or anti-SSB positive (58%), but only 22% met American-European Consensus Group or American College of Rheumatology criteria because the other tests required for disease classification were rarely performed in clinical practice (ocular dryness objective assessment, salivary gland functional or morphologic tests, or salivary gland biopsy). According to the physician diagnosis, age and sex adjusted prevalence of pSS was 10.3/10,000 inhabitants, but according to classification criteria this prevalence was only 2.2/10,000. The analysis based on previous incidence data projected a similar 2015 prevalence rate of 11.0/10,000. Conclusion The prevalence of pSS in this geographically well-defined population was estimated between 2 and 10/10,000 inhabitants. Physicians rarely used tests included in the classification criteria to diagnose the disease in this community setting.

The Incidence and Prevalence of Adult Primary Sjögren's Syndrome in New York County

“…A recent US‐based study of primary SS that was conducted in Olmsted County, Minnesota , with a mostly white population, reported a population‐based prevalence estimate for primary SS based on physician diagnosis of 10.3 per 10,000 residents, which is also higher than our estimate. Even using the conservative AECG definition, the prevalence estimate was still higher than ours at 2.2 (95% CI 1.3,3.1) per 10,000 . A separate study of the same population also showed a higher annual incidence rate of physician‐diagnosed primary SS at 5.9 per 100,000 population (95% CI 4.4,7.4) .…”

“…This observation was corroborated in the recent study by Maciel et al that explored the prevalence of SS in Olmsted County, MN, where the rates for AECG‐confirmed SS were considerably lower than rates for physician‐diagnosed SS . Maciel and colleagues concluded that classification criteria do not accurately reflect the diagnosis of SS in clinical practice, in part because the criteria include invasive tests that are rarely performed in routine care . Importantly, these criteria sets were not developed for diagnostic use in routine clinical practice, but were designed to capture a more homogeneous patient population for the purpose of research and clinical trials .…”

Primary Sjögren's Syndrome Prevalence: What if Sjögren was Right After All? Comment on the Article by Maciel et al

“…Importantly, a recent epidemiologic study conducted in the US through the analysis of a US claims database on the 2004–2012 period identified a prevalence of 4 per 10,000 (i.e., 34,473 cases of 84,253 [424 patients]) . Collectively, taking into account these new results from North America , we feel that there is sufficiently good evidence supporting the idea that primary SS is clearly in the range of rare diseases, in Europe as well as in the US, and should receive appropriate supports as other autoimmune orphan conditions, to help in patient care and therapeutic development.…”

“…We read with interest the study by Maciel et al , reporting an estimation of the prevalence of primary Sjögren's syndrome (SS) in Olmsted County (Minnesota) thanks to the precious Rochester Epidemiology Project (REP) resources. The authors should be commended for conducting such interesting epidemiologic work because, while other prevalence studies were conducted in various parts of the world , there has been a real lack of data from North America so far.…”

“…In the study by Maciel et al , when the authors use various international classification criteria, they obtain a prevalence of 2 per 10,000. Conversely, when they use all the cases diagnosed by physicians, the estimated prevalence increases to 10 per 10,000.…”