OBJECTIVE

To validate the European League Against Rheumatism (EULAR), the American College of Rheumatology (ACR), and the World Health Organization (WHO)/International League Against Rheumatism (ILAR) response criteria for rheumatoid arthritis (RA).

METHODS

EULAR response criteria were developed combining change from baseline and level of disease activity attained during follow up. In a trial comparing hydroxychloroquine and sulfasalazine, we studied construct (radiographic progression), criterion (functional capacity), and discriminant validity.

RESULTS

EULAR response criteria had good construct, criterion, and discriminant validity, ACR and WHO/ILAR criteria showed only good criterion validity.

CONCLUSIONS

EULAR response criteria showed better construct and discriminant validity than did the ACR and the WHO/ILAR response criteria for RA.