A comparison between clinical and laboratory tests in rheumatoid arthritis

Five clinical measurements (clinical score, articular index, visual analogue pain score, visual analogue function score, grip strength) were compared with two laboratory tests (the erythrocyte sedimentation rate and serum C-reactive protein concentration) in 68 patients with rheumatoid arthritis (RA). Patients treated with nonsteroid anti-inflammatory drugs showed clinical deterioration when treatment was interrupted, followed by improvement on resumption; there was no change in the laboratory tests. Patients treated with remission-inducing drugs (RIDs) had improved clinical measurements and also reduced erythrocyte sedimentation rate and serum C-reactive protein levels. Treatment with RID's led to similar trends in both clinical and laboratory tests, but correlation coefficients between the tests at intervals rarely attained statistical significance. The different response times for each test and probably also errors inherent in clinical measurements introduced sufficient variability to account for the discrepancy. Of the clinical tests, 'clinical score' appeared the most satisfactory.