[Epidemiology, prognosis and causes of death in rheumatoid arthritis].

The prevalence of RA in Japan has been reported to be approximately 0.3% of general population and the ratio of male to female patients is 1 to 4. The course of RA is classified into 3 types, those are monocyclic, polycyclic and progressive. The polycyclic and progressive courses of RA would have been ameliorated by the recent progress of medical and surgical treatment and an increased number of patients in monocyclic course would be expected. The mortality rate among RA patients is higher than that of population control. There are causes of death directly related to rheumatoid process itself and resulted from drug treatment. The former includes secondary amyloidosis and basilar impression and the latter includes infection, renal failure and GI bleeding.