Sustained Remission Improves Physical Function in Patients with Established Rheumatoid Arthritis, and Should Be a Treatment Goal: A Prospective Observational Cohort Study from Southern Sweden

Abstract

Objective.It has been proposed that remission should be maintained throughout the course of rheumatoid arthritis (RA); however, the evidence supporting this is limited. Physical function measured by the Health Assessment Questionnaire (HAQ) is a major outcome in RA, and HAQ is shown to be one of the strongest predictors of longterm outcomes. The purpose of this study was to investigate the physical function over a long time in patients with RA who achieved sustained remission (SR) compared with that of patients occasionally achieving remission [non-sustained remission (NSR)].Methods.Patients with RA treated with antitumor necrosis factor and included in the South Swedish Arthritis Treatment Group register were eligible for this study. We identified patients with a Disease Activity Score at 28 joints (DAS28) < 2.6 or Simplified Disease Activity Index (SDAI) ≤ 3.3 at some point and those who achieved SR, i.e., remission during consecutive visits for at least 6 months. The course of functional status was assessed using the HAQ at each visit.Results.Of the 2416 patients, 1177 (48.7%) reached DAS28 remission at some point. SR was achieved by 382 (15.8%) for the DAS28 and 186 (7.7%) for the SDAI criteria. Comparing the SR and NSR groups, HAQ improved during the first 12 months in the DAS28 remission. HAQ continued to improve relatively as long as SR was maintained. A higher proportion of patients in SR reached full physical function.Conclusion.In patients with established RA, physical function measured by the HAQ improves in patients reaching SR compared with patients who only occasionally reach remission. The improvement continues while in remission, which supports that maintaining remission should be a treatment goal.