Geographical studies on rheumatoid arthritis

ABSTRACT

The prevalence of rheumatoid arthritis has been compared in eight population samples in America and Europe, in which routine x rays were taken of the hands and feet. All the x rays were read by one observer. No relationship to lattitude was discovered. The prevalence of "definite" arthritis was not significantly different in the three racial groups included in these surveys, but "probable" disease was more common in the Negro population in Jamaica than in the Amerindians or Caucasians. Radiological evidence of erosive arthritis was more frequent in the Jamaican than in the Amerindian, and the Amerindian than the Caucasian. Serological tests for rheumatoid factor were more often positive in the Amerindian and erosive changes more severe. The implications of these findings are discussed.(Summary)