Comparison of the baseline disease activity of early oligo- and polyarthritis in sequential years

Many early arthritis clinics (EACs) have been started in the last decade in order to detect and treat rheumatoid arthritis early. The present study evaluates whether the disease activity at admission of patients with early oligo- and polyarthritis changed during the period 1993--1998 in two EACs in the Netherlands.

Patients were selected who were diagnosed after one year as having rheumatoid arthritis (RA) or oligo- or polyarthritis (UPA), had a symptom duration of less than 2 years, and were referred from two Dutch EACs between 1993 and 1998. The data from the two clinics were combined and stratified by referral year. Differences in baseline disease characteristics as well as changes in radiological and functional scores after two years of follow-up between referral years were analysed by ANOVA using Bonferroni corrected p levels.

A total of 405 patients (66% females; median age 57 yrs (18-93): 80% diagnosed as RA, the remainder as UPA) were included in the study. The year-groups did not differ significantly in demographic characteristics or in the duration of complaints (median 6 months). The number of patients with a diagnosis of RA declined over the years, as did the mean baseline erythrocyte sedimentation rate (ESR), in RA and UPA patients. The functional status (Health Assessment Questionnaire: HAQ) was enhanced in 1998 compared with the previous years (p < 0.001). Radiographic progression (Sharp/van der Heijde score) after the 2-year follow-up decreased (p < 0.001) in the later referral years compared to the referral group of 1994. Disease modifying anti-rheumnatic drugs (DMARDs) were started in an earlier stage and the prescription rate of sulfasalazine and methotrexate increased over the years, whereas the number of patients not treated with DMARDs declined.

The pattern of patient referral changed over 6 years towards fewer patients who fulfilled the RA diagnosis and a lower ESR (among UPA as well as RA patients), whereas the number of swollen joints and the duration of complaints remained the same. The radiological progression declined over time, probably due to less inflammation at the first visit and the increased use of DMARDs.