Probability of continued low disease activity in patients with recent onset rheumatoid arthritis treated according to the disease activity score.

Abstract

To assess the duration and the probability of maintaining low disease activity once a low disease activity score (DAS) is achieved in recent onset rheumatoid arthritis (RA) patients. The BeSt study is a randomised trial comparing four different treatment strategies in patients with recent onset, active RA. Treatment adjustments were mandatory as long as the DAS was >2.4. If the DAS was <or=2.4, treatment was continued and after 6 months, tapered to maintenance dose. We analysed thrice-monthly DAS calculations in order to assess the duration and the probability of maintaining a DAS <or=2.4. Patients treated with initial combination therapy achieved a DAS <or=2.4 significantly earlier than patients treated with initial monotherapy. Independent of treatment strategy and without treatment adjustments, the probability of a next DAS <or=2.4 3 months after a first DAS <or=2.4 was 74%. The probability increased to 85% after two preceding DAS <or=2.4 and to 88-97% after one to two preceding DAS<1.6. The median duration of a DAS <or=2.4 was 12 months. Once recent onset RA patients achieve a low DAS, the probability of maintaining a low DAS without treatment adjustments is high. This may have implications for the monitoring of patients in daily practice.