Positive Health Online

Abstract

KAIPIAINEN-SEPPANEN and colleagues, Department of Medicine, Kuopio University Hospital, Finland obtained information regarding the incidence of rheumatoid arthritis (RA) and on its recent trends in Finland.

Background

Methodology

The people in the study included those entitled to receive specially reimbursed medication for RA under the national sickness insurance scheme from 5 out of 21 central hospital districts in Finland (population basis approx. 1 million adults) during the 3 years 1980, 1985 and 1990.

Results

The annual incidence of RA in 1980 and 1985, according to the American Rheumatism Association 1987 classification criteria, was 39/100,000 of the population, 16 years of age or older. The combined incidence of rheumatoid factor (RF) factor positive arthritis and RF negative polyarthritis was 46/100,000. Compared with the earlier years, in 1990 there was a decline of 40% in the number of RF negative RA cases. This declining trend was statistically significant.

Conclusion

The decline in the incidence of RF negative RA in Finland may reflect environmental changes specifically affecting the risk of RF negative disease.

References

Kaipiainen-Seppanen O, et al. Incidence of rheumatoid arthritis in Finland during 1980-1990. Ann Rheum Dis. 55(9): 608-11. Sep 1996.