Persistently moderate DAS-28 is not benign: loss of function occurs in early RA despite step-up DMARD therapy

Abstract

Objectives: Current UK management of RA initially employs conventional DMARDs, with biological therapy reserved for DMARD-resistant RA patients with persistently high 28-joint disease activity score (DAS-28). The aim of this study was to examine the effect on patient-reported function of persistently moderate DAS-28 despite modern step-up DMARD therapy in an early arthritis cohort.

Methods: Data were obtained from the Yorkshire Early Arthritis Register, a cohort of early (<12 months) RA patients treated with dose-escalated DMARDs. Change in HAQ exceeding the minimum clinically important difference (MCID) was determined for three values of MCID (0.22, 0.31 and 0.49). Changes in HAQ over Months 6-12 were compared between patients whose DAS-28(ESR) was persistently high (> 5.1 at 6- and/or 9-month visits and at the 12-month visit), persistently moderate (>3.2 and ≤ 5.1) or persistently low (≤ 3.2).

Results: We selected 194 patients for this analysis. Deteriorating HAQ scores were observed in 10.9% of patients with persistently low DAS-28 compared with 21.4% (persistently moderate DAS-28) and 46.7% (persistently high DAS-28), respectively, for MCID = 0.22; 7.3, 14.3 and 20.0% for MCID = 0.31; 5.5, 10.7 and 11.1% for MCID = 0.49.

Conclusions: A high DAS-28 was generally associated with a greater degree of functional decline, but persistent moderate elevation of DAS-28 was associated with important functional deterioration in 10-21% of early RA patients (depending on choice of MCID) following a modern DMARD protocol. A proportion of patients with persistently moderate DAS-28 may therefore benefit from more aggressive therapy than that allowed by current UK recommendations.