Comparison of Disease Activity Score (DAS)28- erythrocyte sedimentation rate and DAS28- C-reactive protein threshold values

• Published in: Annals of the rheumatic diseases 2007-03, Vol.66 (3), p.407-409
• Main Authors: Inoue, Eisuke, Yamanaka, Hisashi, Hara, Masako, Tomatsu, Taisuke, Kamatani, Naoyuki
• Format: Article
• Language: English
• Subjects: Aged; Arthritis, Rheumatoid - diagnosis; Biological and medical sciences; Biomarkers - blood; Blood Sedimentation; C-reactive protein; C-Reactive Protein - analysis; Clinical medicine; Concise Report; CRP; DAS; Disease; Disease Activity Score; Diseases of the osteoarticular system; erythrocyte sedimentation rate; ESR; Female; Health risk assessment; Humans; Inflammatory joint diseases; Laboratories; Male; Medical sciences; Middle Aged; Proteins; receiver operating characteristic; Reproducibility of Results; Rheumatoid arthritis; Rheumatology; ROC; Sensitivity and Specificity; Severity of Illness Index; VAS; visual analogue scale
• ISSN: 0003-4967; 1468-2060
• DOI: 10.1136/ard.2006.054205

Objective: To estimate the disease activity score (DAS)28-C-reactive protein (CRP) threshold values that correspond to DAS28-erythrocyte sedimentation rate (ESR) values for remission, low disease activity and high disease activity in patients with rheumatoid arthritis. Methods: DAS28 data were analysed using a large observational study (Institute of Rheumatology Rheumatoid Arthritis) database of 6729 patients with rheumatoid arthritis. Firstly, the relationship between the DAS28-ESR and the DAS28-CRP values was analysed. Secondly, the best DAS28-CRP trade-off values for each threshold were calculated using receiver operating characteristic (ROC) curves. Results: The correlation coefficient of ESR versus CRP was 0.686, whereas that of DAS28-ESR versus DAS28-CRP was 0.946, showing the strong linear relationship between DAS28-ESR and DAS28-CRP values. DAS28-CRP threshold values corresponding to remission, low disease activity and high disease activity were 2.3, 2.7 and 4.1, respectively. The sensitivity and specificity from the ROC curves were gradually reduced as DAS28 values became lower. Conclusions: This study showed that DAS28-CRP and DAS28-ESR were well correlated, but the threshold values should be reconsidered. As the results were derived from only Japanese patients, it is essential to compare DAS28-CRP threshold values in people of other ethnic groups.