Stiffness, Other Criteria Evaluated In Diagnosis of Rheumatoid Arthritis

Abstract

In an evaluation of the American Rheumatism Association (ARA) criteria for diagnosis of rheumatoid arthritis (RA), a group of investigators found that morning stiffness was of little diagnostic value unless it persisted for at least 10 to 30 minutes. The investigators at the National Institute of Arthritis and Metabolic Disease also determined that pain on motion associated with tenderness is a considerably more accurate diagnostic indicator than either symptom appearing alone. The criteria evaluated were developed by a committee of the ARA for the diagnostic classification of patients. They include morning stiffness, pain on motion or tenderness, joint swelling, skeletal changes as detected by x-ray examination, and the presence of serum rheumatoid factor. If any two criteria are positive, the patient has possible RA, according to ARA standards; three positive criteria constitute probable RA, and five or more constitute definite RA. By determining the frequency with which a given criterion