title: Potential classification criteria for rheumatoid arthritis after two years: results from a French multicenter cohort.
abstract: OBJECTIVE
  To determine agreement among the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) criteria, a diagnosis of rheumatoid arthritis (RA) by a rheumatologist, and other criteria previously used to classify arthritis.
  
  
  METHODS
  We used a nationwide longitudinal prospective cohort of patients with recent-onset arthritis. After 2 years, the patients were classified as receiving disease-modifying antirheumatic drugs (DMARDs), having synovitis, having joint erosions typical of RA, having a rheumatologist diagnosis of RA with >50.0% certainty, having a no better alternative diagnosis with >50.0% certainty, and having a diagnosis of RA using the 1987 ACR criteria and the 2010 ACR/EULAR criteria. Agreement among these criteria was assessed based on Cohen's kappa coefficient, where ≥0.80 = excellent, 0.60-0.79 = good, 0.40-0.59 = moderate, and <0.40 = poor.
  
  
  RESULTS
  Of the 692 evaluated patients, 544 (78.6%) had persistent arthritis (defined as synovitis, ongoing DMARD treatment, or both) after 2 years. Among these 544 patients, 496 (91.2%) were receiving DMARDs. Agreement among all criteria was poor (estimated κ = 0.09-0.43), except when including a rheumatologist diagnosis of RA with >50.0% certainty or a no better alternative diagnosis with >50.0% certainty (estimated κ = 0.69-0.81). The strongest associations with a rheumatologist diagnosis of RA with >50.0% certainty were the 2010 ACR/EULAR criteria and the combination of no better alternative diagnosis, persistent arthritis, 1987 ACR criteria, and positive anti-citrullinated protein antibody.
  
  
  CONCLUSIONS
  Rheumatologist diagnosis of RA with >50.0% certainty after 2 years agreed well with the 2010 ACR/EULAR criteria or a combination of items including no better alternative diagnosis, confirming high value as classification criteria after 2 years of followup.
authors: Centre Hospitalier Universitaire Brest and Université Bretagne Occidentale, Brest, France. Alain.Saraux@chubrest.fr
authors: Alain
authors: A
authors: Saraux
authors: Gabriel J
authors: GJ
authors: Tobón
authors: Mathilde
authors: M
authors: Benhamou
authors: Valérie
authors: V
authors: Devauchelle-Pensec
authors: Maxime
authors: M
authors: Dougados
authors: Xavier
authors: X
authors: Mariette
authors: Francis
authors: F
authors: Berenbaum
authors: Gilles
authors: G
authors: Chiocchia
authors: Anne-Christine
authors: AC
authors: Rat
authors: Thierry
authors: T
authors: Schaeverbeke
authors: Nathalie
authors: N
authors: Rincheval
authors: Olivier
authors: O
authors: Meyer
authors: Bruno
authors: B
authors: Fautrel
authors: Bernard
authors: B
authors: Combe
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012219:Rheumatology / Q000592:standards