Epidemiology of adult rheumatoid arthritis in northwest Greece 1987-1995.

Rheumatoid arthritis (RA) in Greece differs in its clinical, serological, and genetic aspects from that of Northern European countries. We investigated the incidence and prevalence of RA in the district of Ioannina in northwest Greece for the period 1987-1995. We investigated records of patients at rheumatology clinics of university and general hospitals and private clinics in Ioannnina. Diagnosis was by 1987 ACR criteria, and the population data were based on the 1991 national census. Crude and age specific rates were calculated as number of cases per 1000 inhabitants. Age adjusted rates were obtained by the direct method using the European standard population. A total of 428 cases of RA were identified during the study period. Total prevalence of RA was for men 2.05 and for women 4.78 cases/1000 inhabitants, and the total women/men ratio was 2.33. Annual incidence rates fluctuated between 0.15 and 0.36/1000 inhabitants. Our findings suggest a low prevalence and low incidence of RA in northwest Greece. Environmental and/or genetic factors may explain this low frequency of the disease in the population studied.