Longitudinal regression analysis by generalised estimating equations for the relation between clinical variables of inflammation and biomarkers of joint destruction
| Regression coefficient (RC) | Standardised regression coefficient | 95% confidence interval of RC | p Value | |||||
|---|---|---|---|---|---|---|---|---|
| Model 4: lnCTX-I(or II)t = constant + a1.RF (0,1) + a2.treatment (0,1) + a3.RD (0,1) + b1.ESRt + b2.lnCTX-I(or II)t-1 + c1.t + c2.t2 (small letters in italics are regression coefficients: a refers to baseline variables (fixed); b refers to longitudinal variables (time dependent), and c refers to time variables. RF, rheumatoid factor (0 = absent; 1 = present); treatment (0 = sulfasalazine; 1 = COBRA); RD, radiographic damage at baseline (0 = absent; 1 = present); lnCTX-I(or II), the natural logarithm of CTX-I or CTX-II. See text for further explanations). | ||||||||
| DAS28, 28 joint disease activity score. | ||||||||
| (A) Collagen type 1 degradation (CTX-I) | ||||||||
| ESR (mm) | 0.012 | 0.05 | −0.01 to 0.026 | 0.072 | ||||
| Swollen joint count (0–28) | 0.037 | 0.04 | −0.019 to 0.093 | 0.20 | ||||
| Tender joint count (0–28) | 0.032 | 0.03 | −0.018 to 0.081 | 0.22 | ||||
| DAS28 | 0.40 | 0.09 | 0.16 to 0.67 | 0.001 | ||||
| (B) Collagen type II degradation (CTX-II) | ||||||||
| ESR (mm) | 0.0079 | 0.24 | 0.005 to 0.01 | <0.001 | ||||
| Swollen joint count (0–28) | 0.021 | 0.17 | 0.011 to 0.031 | <0.001 | ||||
| Tender joint count (0–28) | 0.007 | 0.08 | −0.001 to 0.021 | 0.089 | ||||
| DAS28 | 0.11 | 0.22 | 0.066 to 0.15 | <0.001 | ||||