Epidemiology of Spondyloarthritis

Abstract

Synopsis Spondyloarthritis (SpA) represents a group of interrelated diseases with common clinical features and a close association with HLA-B27. Figures on the incidence and prevalence of diseases vary highly dependent on methodological differences between studies, the case definition used to classify disease and on the prevalence of HLA-B27 in the population studied. When summarizing the available literature, incidence rates of SpA are mainly based on the ESSG criteria and range between 0.48 and 63/100.000 while prevalence rates vary between 0.01 and 2.5%. For ankylosing spondylitis (AS), the most widely recognized representative of the SpA group of diseases, incidence rates of 0.44-7.3/100.000 and prevalence rates of 0.007-1.7% have been described in studies that were based on the (modified) New York criteria to classify cases. The incidence of psoriatic arthritis (PsA) varied from 3.6 up to 23.1/100.000 in different studies and prevalence between <0.1% and 0.4%, using a variety of classification criteria. The incidence of ReA has been estimated between 0.6 up to 28/100.000 in studies based on different source populations and different case definitions. The newly proposed criteria for axial SpA and peripheral SpA present an attractive new approach to facilitate classification of the SpA into two main subtypes and the axial SpA criteria allow earlier detection of patents with inflammatory back pain. It should be emphasized that these criteria were developed for use in a (specialized) clinical setting and not for large epidemiological studies.

Prevalence of Rheumatoid Arthritis and Spondyloarthritis in Turkey: A Nationwide Study

“…In developed countries, a large number of publications are available on the prevalence of RA and SpA. 1,2 However, in low-and middle-income countries, studies on RA and SpA are sparse. Likewise, in Turkey, epidemiological studies regarding RA and SpA reported to date are very few and regional, rather than nationwide.…”

Assessment of spinal pain

“…Laps and Eskimos have a prevalence of 15e25% and Haida Indians of 50%. There is a relationship between the prevalence of HLA B27 and the prevalence of AS in these populations [40].…”

Nonradiographic axial spondyloarthritis background and confounding factors of this new terminology: an appraisal

“…The Rome criteria were based on expert opinion and allowed classification of patients based on fulfillment of either clinical or imaging criteria. When later evaluated in a population study, the role of the radiographs in showing sacroiliac (SI) joint changes characteristic of AS was found to be unsatisfactory [5]. This led to a revision of the Rome criteria and the creation of the New York (NY) criteria in 1966, which required radiologic evidence of sacroiliitis for fulfillment of the criteria and diagnosis of AS.…”

“…The mNY criteria have been the most widely used in clinical and epidemiological studies and remain an important part of the radiologic arm of the modern ASAS criteria. The main restriction of these criteria is their requirement of radiologic evidence of sacroiliitis, which limits the sensitivity in the diagnosis of early axSpA when radiologic damage may not yet be present, thus delaying the diagnosis up to 8 years [5].…”

“…2). The advantage of the ASAS criteria is the inclusion of MRI, which is able to show SI joint inflammation at an earlier stage of disease, but the inclusion of MRI and HLA-B27 testing makes these criteria infeasible for use in large epidemiologic studies [5].…”