title: 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.
abstract: 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).
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
authors: Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada, and King Khalid University Hospital, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors: Mohammed A
authors: MA
authors: Omair
authors: Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
authors: Edward
authors: E
authors: Keystone
authors: Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada, and Hospital for Special Surgery, New York, New York.
authors: Vivian
authors: V
authors: Bykerk
authors: Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
authors: Daming
authors: D
authors: Lin
authors: Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
authors: Juan
authors: J
authors: Xiong
authors: Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
authors: Ye
authors: Y
authors: Sun
authors: Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
authors: Gilles
authors: 0000-0003-2481-5821
authors: G
authors: Boire
authors: Southlake Regional Health Centre, Newmarket, Ontario, Canada.
authors: J Carter
authors: JC
authors: Thorne
authors: Southlake Regional Health Centre, Newmarket, Ontario, Canada.
authors: Diane
authors: D
authors: Tin
authors: St. Joseph Health Care, University of Western Ontario, London, Ontario, Canada.
authors: Janet
authors: J
authors: Pope
authors: Arthritis Center, University of Manitoba, Winnipeg, Manitoba, Canada.
authors: Carol
authors: C
authors: Hitchon
authors: Institut de Rhumatologie, Montreal, Quebec, Canada.
authors: Boulos
authors: B
authors: Haraoui
authors: Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
authors: Pooneh S
authors: PS
authors: Akhavan
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012074:Remission Induction; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013997:Time Factors