Defining remission in rheumatoid arthritis: Does it matter to the patient? A comparison of multi-dimensional remission criteria and patient reported outcomes

Objectives: In a cross-sectional study, we evaluated the prevalence of 'multi-dimensional remission' (MDR) and its component parameters, assessed using objective measures in a cohort of RA patients in treatment-induced DAS28-remission, and their relationship with patient-reported outcome measures. We sought to confirm the feasibility and face validity of the MDR construct, providing a platform for future longitudinal studies in which its clinical utility might be further established. Methods: 605 patients were selected from an inflammatory arthritis register using DAS28(CRP)<2.6. Demographic, clinical and patients reported outcomes (PRO) data were collected. Ultrasound power doppler synovitis (n = 364) and T-cell subsets (n = 297) were also measured. Remission using clinical parameters was defined as: tender and swollen joint count (TJC/SJC) and CRP all ≤1; ultrasound remission: total power doppler = 0 and T cell remission: positive normalized naïve T-cell frequency. MDR was defined as the achievement of all three dimensions. Results: Overall, only 53% (321/605) of the patients achieved clinical parameters, failures being mainly due to raised CRP (52%), TJC (28)>1 (37%) or SJC (28)>1 (16%). 211/364 (58%) of patients achieved ultrasound remission and 193/297 (65%) patients showed T-cell remission. Complete data were available for 231 patients. MDR was observed in only 35% and was associated with the best (lower) PRO scores (all P ≤ 0.05 vs non-MDR) when compared with the other definitions of remission assessed. The MDR rate was similar in early and established RA patients on b-DMARDs; however, it was lower in established RA patients who received multiple cs-DMARDs (P = 0.011). Conclusions: In this study, MDR, which may represent a state closer to normality, was found to occur in about a third of DAS28-remission patients and was associated with better patient-reported outcome measures. MDR could be a novel optimal treatment target, notably from a patient's perspective. The relevance of these findings needs further assessment.