Prevalence of spondyloarthropathies in an Italian population sample: a regional community-based study

Objective. To estimate the prevalence of spondyloarthropathies (SpA) in an adult population in Marche, a region located in central Italy. Methods. A cross-sectional population-based study was conducted on a target adult population of 20 882. Questionnaires were sent to a random sample of 3664 individuals aged 18 years and over, selected from the lists of 16 general practices. Trained rheumatologists carried out structured visits in which respondent subjects were asked about symptoms of back pain, peripheral arthritis, joint swelling, psoriasis, and the occurrence of diarrhoea and dysuria. A family history of rheumatic disease, psoriasis, or uveitis was assessed. Cases were further classified as ankylosing spondylitis (AS), psoriatic arthritis (PsA), reactive arthritis (ReA), inflammatory bowel disease (IBD)-associated arthritis, and undifferentiated SpA by the European Spondyloarthropathy Study Group (ESSG) criteria. Results. A total of 2155 subjects participated to the study (response rate 58.8%). Twenty-three cases of SpA (18 men, five women, mean age 48.3 +/- 12.1 years) were confirmed, with an overall prevalence of 1.06% [95% confidence interval (CI) 0.78-1.38]. The most common SpA was PsA, with a prevalence of 0.42% (95% CI 0.31-0.61), followed by AS with 0.37% (95% CI 0.23-0.49). Two cases with undifferentiated SpA, two with ReA, and two with IBD-associated arthritis were also observed (0.09%, 95% CI 0.04-0.16). Conclusions. This is the first population-based study that provides an estimate of the prevalence of SpA in Italy. PsA and AS were the most common SpA subsets. Further epidemiological studies are needed to obtain reliable prevalence rates and to better understand our findings.