Sustained rheumatoid arthritis remission is uncommon in clinical practice

Abstract

Introduction: Remission is an important goal of therapy in rheumatoid arthritis (RA), but data on duration of remission are lacking. Our objective was to describe the duration of remission in RA, assessed by different criteria.

Methods: We evaluated patients from the Brigham and Women's Rheumatoid Arthritis Sequential Study (BRASS) not in remission at baseline with at least 2 years of follow-up. Remission was assessed according to the Disease Activity Score 28-C-reactive protein (DAS28-CRP4), Simplified Disease Activity Index (SDAI), and Clinical Disease Activity Index (CDAI) scores, and the recently proposed American College of Rheumatology (ACR)/European League against Rheumatism (EULAR) criteria for remission. Analyses were performed by using Kaplan-Meier survival curves.

Results: We identified 871 subjects with ≥ 2 years of follow-up. Of these subjects, 394 were in remission at one or more time-points and not in remission at baseline, according to at least one of the following criteria: DAS28-CRP < 2.6 (n = 309), DAS28-CRP < 2.3 (n = 275), SDAI (n = 168), CDAI (n = 170), and 2010 ACR/EULAR (n = 158). The median age for the 394 subjects at entrance to BRASS was 56 years; median disease duration was 8 years; 81% were female patients; and 72% were seropositive. Survival analysis performed separately for each remission criterion demonstrated that < 50% of subjects remained in remission 1 year later. Median remission survival time was 1 year. Kaplan-Meier curves of the various remission criteria did not significantly differ (P = 0.29 according to the log-rank test).

Conclusions: This study shows that in clinical practice, a minority of RA patients are in sustained remission.

Figure 1

Subject selection, illustrating the study cohort assembly. For the Kaplan-Meier analyses, we include only subjects with at least 2 years of follow-up, at least one remission time-point with subsequently 12 months or more of follow-up, and who were not in remission at entrance into BRASS. BRASS, Brigham Rheumatoid Arthritis Sequential Study; DAS28-CRP, Disease Activity Score 28-C-reactive protein; ACR, American College of Rheumatology; SDAI, Simplified Disease Activity Index; CDAI, Clinical Disease Activity; EULAR, European League Against Rheumatism.

Figure 2

Kaplan-Meier survival curves for subjects maintaining remission according to various remission definitions, demonstrating the Kaplan-Meier survival curves for the percentage of subjects maintaining remission over time. Curves represent the following remission definitions: blue DAS28-CRP < 2.6 (blue), DAS28-CRP < 2.3 (red), CDAI (green), SDAI (yellow), and 2010 ACR/EULAR (black dotted). Beneath the figure, we include the number of subjects in remission and the percentage of subjects in remission compared with the total number of subjects included in the analysis at each time point. For instance, after 3 years, 37 of 59 patients (63%) were still in remission according to the DAS28-CRP < 2.6. Notice that not 91 but 59 subjects are evaluated at 3 years, because 32 subjects were censored, as not all patients have same duration of follow-up (open cohort).

Figure 3

Kaplan-Meier survival curves for subjects maintaining DAS28-CRP < 2.6 remission, stratified according to (a) gender, (b) serologic status, (c) disease duration. We demonstrate the Kaplan-Meier survival curve for the percentage of patients maintaining DAS28-CRP < 2.6 remission over time. Patients are stratified according to different patient and disease characteristics. Beneath the figure, we include the number of subjects in remission and the percentage of subjects in remission compared with the total number of subjects included in the analysis at each time point.