Background Recently, an American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) collaboration developed new classification criteria for rheumatoid arthritis (RA).

Objective To evaluate the diagnostic and discriminative ability of these new criteria compared with the 1987 ACR criteria and the Visser decision rule.

Methods 455 patients with early arthritis were studied. The diagnostic performance of the criteria was evaluated using methotrexate treatment within 1 year, expert opinion RA and erosive disease as ‘gold standards’. Erosive disease was defined as a 0–3 year change in radiographic score of ≥5.

Results The discriminative ability of the three criteria sets (2010 ACR/EULAR, 1987 ACR criteria and Visser algorithm) was similar with areas under the curve of 0.71–0.78 (‘gold standard’ methotrexate), 0.74–0.80 (gold standard expert opinion RA) and 0.63–0.67 (gold standard erosive disease after 3 years). The sensitivity of the 2010 ACR/EULAR criteria was highest with 0.85 (gold standard methotrexate). 86% of patients with RA and 51% of ‘non-RA’ patients according to the new criteria used methotrexate.

Conclusion The 2010 ACR/EULAR criteria were slightly more sensitive, but otherwise performed similarly to the older criteria. A high percentage of ‘non-RA’ patients used methotrexate, the gold standard for RA. The ability of the new criteria to identify patients with erosive disease was low, possibly owing to the effect of intensive treatment.