Clinical pattern of pain in rheumatoid arthritis

Clinical pattern of pain in rheumatoid arthritis. La Montagna G, Tirri R, Baruffo A, Preti B, Viaggi S. Source Insitute of Clinical Medicine, Faculty of Medicine, 2nd University of Naples, Italy. Abstract OBJECTIVE: To evaluate whether rheumatoid arthritis (RA) is associated with a characteristic clinical pattern of pain which may be useful as a criterion to differentiate RA from other rheumatic diseases. METHODS: 2300 patients from the ReumaLink data bank project with definite rheumatic diseases were studied. Of these 907 patients (39.5%) fulfilled the ARA/ACR revised criteria for RA, while 1393 had rheumatic diseases other than RA. The following diagnostic attributes of pain were considered: localization, symmetry, continuity, modulation, relationship with time and with loads/movements, tenderness. RESULTS: After a descriptive analysis, some pain characteristics were selected individually and others were combined. Only 8 variables were considered for a predictive analysis. Univariate analysis showed that symmetric pain is the most potent discriminating item, with 82.2% sensitivity, 69.2% specificity, a 61% positive predictive value and a 83.3% negative predictive value. A higher probability of RA was present in patients with symmetric pain than in those with asymmetric pain (odds ratio = 7.8). A multivariate analysis performed on 1627 patients showed that a specific clinical pattern of pain (symmetrical pain, pain following joint pressure, mainly present at night or in the morning, continuous) could predict RA patients with a 68.9% likelihood. The lack of these symptoms excluded RA with 92% probability. CONCLUSION: The clinical pattern of pain defined by us can predict RA with a 70% probability. This value reaches 86% when the variables "pain in a fixed joint" and "pain decreased by load/movements" are added. These results indicate that determining the clinical pattern of pain is a useful screening tool for suspected RA, in particular early in the disease course