The prevalence of rheumatoid arthritis in Sweden

The aim of this study was to ascertain the prevalence of rheumatoid arthrit is (RA) in a Swedish general adult population A questionnaire about chronic pain was mailed to a total of 3928 subjects who were chosen as a random sa mple of the population in two communities in the county of Halland. All per sons answering affirmatively to questions intended to identify patients wit h RA were invited to a clinical examination. X-rays of hands and feet, and analyses of rheumatoid factor and C reactive protein were performed provide d that the patients fulfilled two or more of the five clinical items of the 1987 ARA criteria. Furthermore, non-participants were searched for in a pa tient register and in medical records from the local rheumatology unit in a n attempt to identify further cases. Using the modified 1987 ARA criteria f or population studies the prevalence rate of RA was calculated to 0.51% (95 % CI=0.31-0.79).