Twenty eight joint count disease activity score in recent onset rheumatoid arthritis using C reactive protein instead of erythrocyte sedimentation rate

DAS28 based on ESR ranged from 0.50 to 8.50 (mean (SD) 4.04 (1.48)) and DAS28/CRP ranged from 1.14 to 8.00 (mean (SD) 3.68 (1.46)). [...]the mean (SD) DAS28/ESR of 4.04 (1.48)was not statistically different from DAS28/CRP (3.68 (1.46)). [...]the correlation between ESR and plasma CRP in this study was within the same magnitude as that reported in previous studies on RA. 1, 4 Although the two values were by no means interchangeable, the correlation between the "orthodox" DAS28 and DAS28 based on plasma CRP was remarkably high, because the weight of the laboratory test is low and thus has only a small impact on the disease activity score compared with the other measures.