In 2004 Ward analyzed 63 rheumatoid arthritis (RA) clinical trial studies with 90 active disease modifying antirheumatic drug treatment arms and demonstrated that erythrocyte sedimentation rate (ESR) was more sensitive to change than C-reactive protein (CRP) at 12 weeks and 24 weeks of treatment, with mean effect size differences of 0.09 to 0.11 units1. It is puzzling that Crowson, et al, authors from the Mayo Clinic and Centocor, address the issues of ESR versus CRP again, and with correlation analyses2. If we get their point, it is that it doesn’t matter which test is used in a clinical trial as they are both about as effective (or ineffective). This conclusion comes primarily from finding similar levels of correlation between swollen joint count and ESR and CRP, and through analysis …
Address correspondence to Dr. Wolfe. E-mail: fwolfe{at}arthritis-research.org