Background The spondyloarthritis (SpA) prevalence has shown a trend to increase in the last two decades, in line with better recognition of the disease as well as the use of new classification criteria (1). The need to estimate and compare the SpA prevalence accross Europe was recognized.

Objectives to estimate the SpA prevalence in several European countries: France, Turkey, Lithuania and Serbia using identical methodology and sampling; to standardize the results with reference to the European Standard Population by using direct method.

Methods A two-step approach was taken. First, a unique detection Questionnaire, covering self-reported diagnosis, SpA classification criteria (ESSG 1991), personal and family history for SpA (2), previously translated and validated for each of the participating countries, was administered to a population sample. A two-stage sampling was carried out 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. Second, diagnoses were confirmed by rheumatologists. Results were standardized by age and sex using the European Standard Population, defined as EU-27+EFTA, 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 29 cases in France (37.9% male), 18 in Turkey (16.7% male), 27 in Lithuania (55.6% male) and 16 in Serbia (37.5% male). Estimates of the SpA prevalence standardized for age and sex are given in Table 1.

Conclusions Age- and sex-standardized SpA prevalence estimates in France, Turkey and Serbia were in line, but were as twice as high in Lithuania, confirming a north-south decreasing gradient using homogenous sampling and case ascertainment method. Standardized SpA prevalence estimates in men and women were similar in France and Serbia, but not in Turkey and Lithuania. This study adds to previous observation on similarity of RA and SpA prevalence estimates.

1. Zlatković-Švenda M, Stojanović R, Šipetić-Grujičić S, et al. Prevalence of spondyloarthritis in Serbia: a EULAR endorsed study. Ann Rheum Dis. 2015; 74(10):1940–2.

2. Guillemin F, Saraux A, Fardellone P, et al. Detection of cases of inflammatory rheumatic disorders: performance of a telephone questionnaire designed for use by patient interviewers. Ann Rheum Dis 2003;62:957–63.

3. Saraux A, Guillemin F, Guggenbuhl P, et al. Prevalence of spondyloarthropathies in France: 2001. Ann Rheum Dis 2005;64:1431–5

4. 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