Decrease in Rheumatoid Arthritis Rate Causes Speculation as to Cause

Results of a new study suggest rheumatoid arthritis may be on the decline, causing researchers to speculate as to whether the disease could be the result of environmental factors.

Researchers at the Mayo Clinic in Rochester, Minnesota reviewed medical records of 609 rheumatoid arthritis patients in that city over a 40-year period. The average age at diagnosis, 58 years, remained the same throughout the study period.

The overall age-and sex-adjusted incidence of rheumatoid arthritis among Rochester residents aged 18 or over decreased from 61.2 patients per 100,000 between 1955 and 1964 to 32.7 per 100,000 by 1985-1994, the researchers reported in Arthritis and Rheumatism.

The decrease in the incidence of rheumatoid arthritis was more marked in women than men,the researchers added.

Other sources: Arthritis and Rheumatism