The objective of this study was to assess the prevalence of rheumatoid arthritis (RA) in the population of a city of 70,000 inhabitants located in Buenos Aires, Argentina.
Based on the hypothesis that RA is an underdiagnosed disease in Argentina, a capture-recapture method was applied. A local registry of RA patients of Luján City was taken as the primary source; a telephone survey was specifically carried out as a secondary source of information. Patients suspected of having RA were referred to a local hospital to be examined by a team of 12 rheumatologists. Anamnesis and physical examination were followed by hand and foot radiography and erythrocyte sedimentation rate and rheumatoid factor measurements.
According to the American College of Rheumatology criteria, a prevalence rate of 0.94% (95% confidence interval [CI], 0.86%-1.02%) was found in the surveyed population; in agreement with other studies, this prevalence was higher in women when compared with men (for female, 1.54% [95% CI, 1.40%-1.69%]; for male, 0.40% [95% CI, 0.32%-0.49%]).
The prevalence of RA in a representative sample of the population of a city from the central region of Argentina seems to be close to 1%.