title: Disease Activity Score 28 (DAS28) using C-reactive protein underestimates disease activity and overestimates EULAR response criteria compared with DAS28 using erythrocyte sedimentation rate in a large observational cohort of rheumatoid arthritis patients in Japan.
abstract: OBJECTIVE
  To compare disease activity and the improvement of disease activity evaluated between by Disease Activity Score 28 using erythrocyte sedimentation rate (DAS28-ESR) and by DAS28 using C-reactive protein (DAS28-CRP) in Japanese patients with rheumatoid arthritis (RA).
  
  
  METHODS
  Data from 3073 RA patients registered in the large cohort database (NinJa: National Database of Rheumatic Diseases by iR-net in Japan) of 2003 was used to calculate DAS28-ESR and DAS28-CRP and disease activities were evaluated. Improvements in disease activities were also evaluated according to the European League Against Rheumatism (EULAR) response criteria in 1482 RA patients whose DAS28-ESR and DAS28-CRP could be calculated from data for both 2002 and 2003.
  
  
  RESULTS
  The mean value of DAS28-CRP (3.59, SD 1.25) was significantly smaller than that of mean DAS28-ESR (4.31, SD 1.32) (p < 0.0001). The number of patients who satisfied the criteria of remission was 297 (9.7%) in DAS28-ESR versus 705 (22.9%) in DAS28-CRP and the number of patients with high disease activity was 842 (27.4%) versus 357 (11.6%) for DAS28-ESR and DAS28-CRP, respectively; there was a significant difference between the two (p < 0.0001). Change of respective DAS28 was significantly correlated (DeltaDAS28-ESR -0.05, SD 1.14 versus DeltaDAS28-CRP -0.10, SD 1.10) (p < 0.0001); however, the number of "good response" patients was significantly different (p < 0.03) between DAS28-ESR (97 patients, 6.5%) and DAS28-CRP (136 patients, 9.2%).
  
  
  CONCLUSIONS
  DAS28-CRP significantly underestimated disease activity and overestimated the improvement in disease activity compared with DAS28-ESR. DAS28-CRP should be evaluated using different criteria from that for DAS28-ESR.
authors: Department of Rheumatology, Sagamihara National Hospital, National Hospital Organization 18-1, Sakuradai Sagamihara-city, Kanagawa, 228-8522, Japan. t-matsui@sagamihara-hosp.gr.jp
authors: Toshihiro
authors: T
authors: Matsui
authors: Yoshiaki
authors: Y
authors: Kuga
authors: Atsushi
authors: A
authors: Kaneko
authors: Jinju
authors: J
authors: Nishino
authors: Yoshito
authors: Y
authors: Eto
authors: Noriyuki
authors: N
authors: Chiba
authors: Masayuki
authors: M
authors: Yasuda
authors: Koichiro
authors: K
authors: Saisho
authors: Kota
authors: K
authors: Shimada
authors: Shigeto
authors: S
authors: Tohma
mesh_terms: D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000188:drug therapy; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D018501:Antirheumatic Agents; D015415:Biomarkers; D005938:Glucocorticoids; D002097:C-Reactive Protein