Prevalence of rheumatoid arthritis in France: 2001

Background: Prevalence estimates of rheumatoid arthritis ( RA) vary across Europe. Recent estimates in southern European countries showed a lower prevalence than in northern countries. Objectives: To estimate the prevalence of RA in France in a multiregional representative sample in the year 2001. Methods: A two stage random sample was constituted in seven areas ( 20 counties) from the national telephone directory of households and by the next birthday method in each household. Patient-interviewers, member of self help groups, were trained to administer telephone surveys using a validated questionnaire for case detection of inflammatory rheumatism, and conducted the survey under quality control. All suspected cases of RA were confirmed by their rheumatologist or by clinical examination. Prevalence estimates after probability sampling correction were standardised for age and sex ( national census 1999). Results: An average response rate of 64.7% ( two stages combined) led to a total of 9395 respondents. Standardised prevalence was 0.31% (95% confidence interval 0.18 to 0.48) for RA, 0.51% in women and 0.09% in men, with a higher age-specific prevalence in the 65 - 74 year age band. A geographical analysis of county clustering showed significant variation across the country. Conclusion: This national multiregional cooperative study demonstrates the usefulness of working in association with patients of self help groups. It showed a similar prevalence of RA to that of the spondyloarthropathies estimated concomitantly during the survey. It provides a reliable basis for definition of population targets for healthcare delivery and drug treatments.