Prevalence of spondyloarthropathies in France: 2001

Objective: To estimate the prevalence of spondyloarthropathies (SpAs) in France in a multiregional representative sample in the year 2001. Methods: A two stage random sample was constituted in seven areas from the national telephone directory and the next birthday method in each household. Interviewers were patient-members of self help groups trained to administer telephone surveys using a validated questionnaire for detecting inflammatory joint disease. Quality of data collection was controlled periodically. SpA was confirmed by the patient's rheumatologist or by clinical examination. Prevalence estimates after probability sampling correction were standardised for age and sex ( 1999 national census). Results: Among the 15 219 anonymous telephone numbers selected, 3.6% were places of work or secondary residences and were excluded. The phone interview participation rate ranged across regions from 55.1 to 69.9%. 3554 men and 5841 women were included in the study. Twenty nine cases of SpA were confirmed. All but one fulfilled ESSG criteria. Mean age was 47 years ( range 21 - 78). The overall prevalence standardised for age and sex was 0.30% (95% confidence interval (CI) 0.17 to 0.46). Prevalence was similar in women (0.29% ( 95% CI 0.14 to 0.49)) and men (0.31 % ( 95% CI 0.12 to 0.60)). Geographical analysis by department clustering found no significant differences. The prevalence of SpA was as high as that of rheumatoid arthritis. Conclusion: Prevalence of SpA in France was 0.30% in 2001, with no difference between women and men. Ankylosing spondylitis and psoriatic arthritis were the most common SpA subsets.