Low incidence of rheumatoid arthritis in France.

The incidence of rheumatoid arthritis (RA) was estimated in the Lorraine district, eastern France, over the period 1986-1989. Cases were identified from in- and outpatients at the district Rheumatology Hospital Centre, private rheumatologists, general practitioners and by regional media announcements. Supplementary cases resident in the area were sought by extending the procedure to adjacent districts. The population count was obtained from the national Census. An overall age-adjusted incidence rate of 8.8/100,000 was found using the 1987 ACR criteria (12.7/100,000 in females, 4.7/100,000 in males; sex ratio = 2.65) and 9.5/100,000 using the 1958 ARA criteria (definite and classic RA). These rates were compared, using the same standard population, with the age-adjusted incidence rates in other incidence studies mainly conducted in Caucasian populations. The RA incidence rates appeared lower in France than in any other country in Europe, USA and Japan.