To compare application of the 1987 American College of Rheumatology (ACR) and 2010 ACR/European League Against Rheumatism (EULAR) classification criteria for diagnosing rheumatoid arthritis (RA) in clinical practice.
The medical records of patients with early arthritis attending the Rheumatology Department, Umeå University Hospital (n = 1026) were analysed. Patients with synovitis in at least one joint, no diagnosis other than RA being better for explaining the synovitis, and duration of symptoms less than 1 year at first visit, and at least 1 year of follow-up were included consecutively. Fulfilment of the 1987 and 2010 criteria at baseline was evaluated. Sensitivity and specificity for each criterion set, where estimated by using the outcome measures: initiation of methotrexate (MTX) therapy during the first year, and a clinical diagnosis of RA at the 1-year follow-up. Radiographs of hands and feet were evaluated using the Larsen score.
The study included 313 patients, of whom 56% fulfilled the 1987 ACR criteria, 74% the 2010 ACR/EULAR criteria, and 53% both sets of criteria at baseline. The sensitivity/specificity for the 1987 and 2010 criteria with MTX within the first year as the outcome measure was 0.68/0.79 and 0.84/0.54, respectively, and with a diagnosis of RA at follow-up 0.72/0.83 and 0.91/0.65, respectively. Older patients (i.e. ≥ 60 years) more often fulfilled the 2010 criteria. Patients who fulfilled the 2010 ACR/EULAR but not the 1987 ACR criteria had a lower Larsen score at inclusion and after 2 years.
Compared with the 1987 ACR criteria, the 2010 ACR/EULAR criteria have higher sensitivity but lower specificity, especially in patients aged ≥ 60 years. The 1987 ACR criteria are suggested to predict a more erosive disease.