Low disease activity state with corticosteroid may not represent 'true' low disease activity state in patients with rheumatoid arthritis.

Objective: Corticosteroids constitute one of the most common treatments of RA. The purpose of this study is to investigate whether long-term corticosteroid use suppresses the progression of disability in RA patients with low disease activity state.

Methods: Data collected from a large observational cohort of RA patients at our institution were analysed for 214 RA patients whose disease activity score (DAS) 28 and HAQ were available consecutively from October 2000 to October 2004. All 214 patients had average DAS 28 <3.2, meaning only those who had well-controlled RA disease activity were chosen as subjects. The subjects were divided into steroid users who received continuous corticosteroids every month and non-steroid users who did not receive consecutive corticosteroids continuously every month.

Results: Fifty-five patients (25.7%) were corticosteroid users and 159 (74.3%) were non-users. Average prednisolone for the former group was 4.2 mg/day. No significant differences were observed among baseline variables and RA disease activity variables. However, for steroid users, HAQ progressively worsened with time and for non-steroid users, HAQ progressively improved.

Conclusions: Although DAS 28 and other variables may suggest well-controlled RA disease activity, functional capacity of patients on low-dose corticosteroids deteriorated. Thus, low disease activity state with corticosteroid may not represent the 'true' low disease activity state. Along with the achievement of a low disease activity state, long-term efficacy, prognosis, and the quality of remission need to be also considered in the tight control of RA activity.