CLINICAL-ASSESSMENT OF THE 1987 AMERICAN-COLLEGE-OF-RHEUMATOLOGY CRITERIA FOR RHEUMATOID-ARTHRITIS

The 1987 American College of Rheumatology (ACR) criteria for the class ification of rheumatoid arthritis (RA) were clinically assessed. These criteria do not include findings of synovial fluid (SF) analysis and require no exclusion criteria. We have studied sequential patients wit h arthritis seen in four rheumatology centers in the Philadelphia area . Classifications by the ACR criteria were compared with our clinical diagnoses. Two hundred ninety eight patients were evaluated, 113 with RA and 185 with other diagnoses. Classifications as RA by the ACR crit eria corresponded to our clinical diagnosis in 95% of the cases, corro borating the high sensitivity previously reported. However, we found a lower specificity (73%) than that reported (89%). False positive clas sifications as RA were found in 71% of patients with psoriatic arthrit is, 48% of patients with SLE, and 31% of patients with gout. The speci ficity could be improved to 89% by excluding disorders with obvious di stinguishing extraarticular features such as psoriasis or by SF findin gs of monosodium urate crystals. Awareness of these possible sources o f confusion will further increase the teaching and epidemiologic value of these useful simplified criteria.