Background Various rheumatoid arthritis (RA) prevalence estimates have been reported across Europe, but differences in methodology made it difficult to disentangle true heterogeneity (1). A unique RA prevalence survey method, comprising similar sampling and results interpretation, was needed.
Objectives to estimate the RA prevalence in France, Turkey, Lithuania and Serbia using a unique methodology and to use direct method for standardization of results with reference to the European Standard Population.
Methods In a first detection phase, a unique Questionnaire covering signs, symptoms, self-reported diagnosis and classification criteria for RA (ACR 1987) (2), previously translated and validated for each of the participating countries, was conducted on population sample. Two-stage random sampling was implemented on seven areas covering 20 counties in France, seven geographical regions covering 25 administrative provinces in Turkey, two largest cities- Vilnius and Kaunas in Lithuania and two geographical regions covering four counties in Serbia. In a second confirmation phase, diagnoses were confirmed by rheumatologists. Results were standardized by age and sex using the European Standard Population, defined as EU-27+EFTA, based on the 2010 estimates.
Results Detection Questionnaire was administered by telephone on 15219 persons in France (3), 6558 in Lithuania (4) and 6213 in Serbia (1), with 64.7%, 64.7% and 63.3% response rate, respectively. In Turkey, Questionnaire was administered face-to-face on 4012 persons. Diagnoses were confirmed for 32 cases in France (93.7% female), 25 in Turkey (92.0% female), 39 in Lithuania (100.0% female) and 23 in Serbia (82.6% female). Overall standardized RA prevalence estimates are given in Table 1.
Conclusions Age- and sex-standardized RA prevalence estimates in France were in line with Serbia, but lower than in Turkey and Lithuania. Standardized RA prevalence estimates in men were similar for all countries, up to 0,19%. Standardized women RA prevalence was largely heterogenous, resulting in diverse overall European RA prevalence, from 0,29% to 0,57%. The use of a unique survey method with similar sampling and case ascertainment has shown genuine heterogeneity of the RA prevalence in women across Europe.
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Adomaviciute D, Pileckyte M, Baranauskaite A et al. Prevalence survey of rheumatoid arthritis and spondyloarthropathy in Lithuania. Scand J Rheumatol 2008;37:113–9.
Acknowledgement Study supported by a EULAR grant
Disclosure of Interest None declared