Prevalence of rheumatoid arthritis in Italy: the Chiavari Study

Abstract

Objective: To ascertain the prevalence of rheumatoid arthritis (RA) in an Italian general population.

Methods: The study was performed in the years 1991-92 in Chiavari, a small town located on the Ligurian coast, and involved 4456 subjects aged 16 years or more from four general practices. The subjects received a postal questionnaire developed to detect patients with current or past inflammatory joint diseases. The age and sex distribution of the sample were similar to those of the Italian population from the 1992 census. Patients reporting a history of joint swelling in at least a pair of symmetrical joints were reviewed by a rheumatologist. The clinical records of non-responders and responders who failed to attend the clinic were also reviewed.

Results: 3294 of 4456 (73.9%) subjects answered to the questionnaire. The mean (SD) age of the 3294 responders was 48.3 (19.3) years; 53.7% of them were female. Swelling in at least two symmetrical joints was reported by 230 subjects (7%). Among them, 11 patients fulfilling the 1987 ARA criteria for RA were identified. The prevalence of RA was 0.33% (95% CI 0.13, 0.53) in the general population, 0.13% (95% CI 0, 0.31) in men, and 0.51% (95% CI 0.18, 0.84) in women.

Conclusions: These data are consistent with the results of three earlier studies published in the fifties in the Italian literature and confirm that the prevalence of RA is low in Italy and has remained unchanged in the last 40 years.

Figure 1

A rough description of the prevalence of rheumatoid arthritis derived from various studies performed in Europe. Circle size is proportional to the number of people at denominator and the gray tint is proportional to RA prevalence. Note that the results of the different studies are not completely comparable because some methods were different. A list of the relevant references is available on request.