Demographic and disease activity measures at baseline and at 52 weeks
| Demographic and disease activity at baseline | COBRA (n=81) | COBRA-light (n=81) |
|---|---|---|
| Female, n (%) | 54 (66) | 58 (69) |
| Age, years | 53 (13) | 51 (12) |
| Disease duration, weeks | 22 (17) | 25 (22) |
| Rheumatoid factor, n (%) | 47 (58) | 49 (59) |
| Anti-CCP positive, n (%) | 50 (61) | 55 (66) |
| DAS44 | 4.09 (0.7) | 3.96 (0.9) |
| DAS44-CRP | 4.44 (1.0) | 4.21 (1.2) |
| DAS28 | 5.55 (1.1) | 5.32 (1.2) |
| Tender joints | 15.7 (7.0) | 14.6 (7.9) |
| Swollen joints | 14.1 (5.1) | 12.4 (5.4) |
| HAQ | 1.36 (0.7) | 1.37 (0.7) |
| SHS | 2.66 (6.5) | 1.61 (4.0) |
| ESR, mm/h | 27.0 (14.5 to 44.5) | 27.0 (12.0 to 48.0) |
| CRP, mg/L | 13.0 (4.5 to 27.0) | 13.0 (4.0 to 30.5) |
| Patient assessment disease activity, by VAS, mm | 60.2 (21.6) | 65.6 (23.5) |
| Patient assessment of pain, by VAS, mm | 60.1 (22.9) | 57.8 (25.4) |
| Patient global assessment, by VAS, mm | 60.5 (21.9) | 58.3 (25.3) |
| Physician assessment disease activity, by VAS, mm | 51.2 (14.5) | 48.2 (16.6) |
| Disease activity and response at week 52* | β (95% CI) | p Value | ||
|---|---|---|---|---|
| DAS44 | 1.70 (1.0) | 1.88 (1.0) | 0.19 (−0.07 to 0.45) | 0.15 |
| DAS44-CRP | 1.71 (1.2) | 1.69 (1.1) | 0.03 (−0.27 to 0.33) | 0.74 |
| DAS28 | 2.49 (1.3) | 2.71 (1.3) | 0.24 (−0.08 to 0.57) | 0.15 |
| Tender joints | 5.3 (7.2) | 5.0 (6.0) | −0.17 (−1.99 to 1.64) | 0.85 |
| Swollen joints | 2.6 (3.6) | 2.3 (2.6) | −0.79 (−2.12 to 0.55) | 0.25 |
| HAQ | 0.57 (0.5) | 0.61 (0.6) | 0.07 (−0.08 to 0.21) | 0.35 |
| ESR, mm/h† | 6.0 (2.5 to 1.0) | 2.5 (1.0 to 4.3) | 0.42 (0.20 to 0.64) | <0.01 |
| CRP, mg/L† | 2.5 (2.0 to 4.0) | 7.5 (3.0 to 16.0) | 0.05 (−0.17 to 0.26) | 0.65 |
| Patient assessment disease activity, by VAS, mm | 30.1 (27.2) | 26.1 (26.0) | −5.78 (−11.89 to 0.34) | 0.06 |
| Patient assessment of pain, by VAS, mm | 29.3 (26.4) | 24.9 (25.5) | −3.55 (−9.38 to 2.28) | 0.23 |
| Patient global assessment, by VAS, mm | 31.2 (26.2) | 28.8 (26.2) | −0.96 (−6.71 to 4.79) | 0.74 |
| Physician assessment disease activity, by VAS, mm | 18.5 (16.2) | 16.7 (14.7) | −0.58 (−4.32 to 3.16) | 0.76 |
| Differences in outcome after 52 weeks‡ | ||||
| ΔDAS44 | −2.41 (1.2) | −2.02 (1.1) | 0.21 (−0.09 to 0.52) | 0.17 |
| AUC DAS44 | 104 (76 to 124) | 108 (74 to 135) | 0.00 (−0.00 to 0.00) | 0.33 |
| ΔSHS | 0.49 (1.6) | 0.59 (1.4) | 0.18 (−0.27 to 0.63) | 0.42 |
| ΔErosion | 0.18 (0.4) | 0.30 (0.8) | 0.19 (0.00 to 0.37) | 0.05 |
| ΔJSN | 0.31 (1.5) | 0.27 (0.8) | −0.05 (−0.43 to 0.33) | 0.80 |
| Response measures at week 52 | RR (95% CI) | p Value | ||
| Remissions, n (%)§ | ||||
| Clinical remission (DAS44 <1.6) | 38 (47) | 31 (38) | 0.85 (0.64 to 1.13) | 0.18 |
| ACR/Boolean remission | 12 (15) | 14 (17) | 1.03 (0.90 to 1.18) | 0.67 |
| EULAR response, n (%)¶ | ||||
| Non-responders | 5 (6) | 5 (6) | 1.00 (0.53 to 1.90) | 1.00 |
| Moderate responder, but not good responders | 16 (50) | 23 (28) | ||
| Good responders | 56 (69) | 49 (60) | ||
| ACR response, n (%)¶ | ||||
| ACR non-responders | 19 (23) | 20 (25) | OR 1.03 (0.71 to 1.49) | 0.73 |
| ACR20, but not ACR50 | 12 (15) | 15 (18) | ||
| ACR50, but not ACR70 | 20 (25) | 14 (17) | ||
| ACR70 | 25 (31) | 28 (35) | ||
Data are expressed as mean (SD) unless otherwise stated. Significance between groups was tested with Generalised Estimating Equation (GEE) analyses, linear regression and relative risk. All regression analyses were corrected for baseline values.
*GEE analyses.
†Analyses based on lnESR and lnCRP.
‡Linear regression analyses.
§Relative risk analyses.
¶χ2 for trend analyses.
ACR, American College of Rheumatology; anti-CCP, anti-cyclic citrullinated peptide; AUC, area under the curve; COBRA, COmbinatietherapie Bij Reumatoïde Artritis; CRP, C-reactive protein; DAS28, 28-joint count Disease Activity Score; DAS44, 44-joint count Disease Activity Score; DAS44-CRP, 44-joint count Disease Activity Score based on CRP; ESR, erythrocyte sedimentation rate; EULAR, European League against Rheumatism; HAQ, Health Assessment Questionnaire; JSN, joint space narrowing; RR, relative risk; SHS, Sharp/ van der Heijde score; VAS, visual analogue scale.