Predicting Low Disease State and Remission in Early Rheumatoid Arthritis in the First Six Months, Comparing the Simplified Disease Activity Index and European League Against Rheumatism Response Measures: Results From an Early Arthritis Cohort

Arthritis Care Res (Hoboken). 2017 May;69(5):737-741. doi: 10.1002/acr.22983. Epub 2017 Apr 7.

Abstract

Objective: To compare the European League Against Rheumatism (EULAR) and Simplified Disease Activity Index 50% (SDAI50) response measures (RMs) and their impact on future response to treatment in patients with early rheumatoid arthritis (ERA).

Methods: Biologic agent-naive ERA patients from the Canadian Early Arthritis Cohort study with complete data at baseline, 3, and 6 months were evaluated. Kappa statistics were used to evaluate the agreement between the EULAR (moderate or good response) and SDAI50 RMs. The RMs at 3 months were also compared for their ability to predict low disease activity state (LDAS) or remission (REM) at 6 months.

Results: A total of 1,124 patients were evaluated. Of those, 215 patients (30%) and 294 patients (45%) failed to achieve a EULAR and SDAI50 response, respectively. There was a good agreement between EULAR and SDAI50 RMs with a kappa of 0.59 (95% confidence interval 0.53-0.66). Throughout the range of disease activity, the SDAI50 response was shown to be more stringent than the EULAR response. Multivariable linear regression analysis demonstrated that both RMs at 3 months were associated with LDAS or REM at 6 months, and SDAI50 had a more significant impact on this outcome compared to the EULAR response.

Conclusion: There is a good agreement between the EULAR and SDAI50 RMs. Although a minority of patients have discordant RMs at each end of the disease activity spectrum at baseline, the SDAI50 response at 3 months appears to be a more significant predictor of outcomes at 6 months than EULAR response.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Arthritis, Rheumatoid / diagnosis*
  • Arthritis, Rheumatoid / epidemiology
  • Arthritis, Rheumatoid / pathology
  • Canada / epidemiology
  • Cohort Studies
  • Disease Progression
  • Female
  • Humans
  • Linear Models
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Remission Induction
  • Reproducibility of Results
  • Severity of Illness Index*
  • Time Factors