Juvenile rheumatoid arthritis. A comparison of patients from the USSR and USA.

Juvenile rheumatoid arthritis (JRA) in the Union of Soviet Socialist Republics (USSR) and the United States (USA) shows a remarkable similarity in age of disease onset, subtype onset, frequency, and most laboratory measurements. There is variation in the therapeutic approach with heavier reliance on aspirin in the USA. The evolution of JRA from onset subtype to final subtype over 5 years was the same in both groups and was independent of the type of therapy.