Maxime Verhoeven

66 Chapter 4 Figure 1 ROC curve for the prediction of insufficient response (DAS28>3.2) to MTX after 3 months of treatment. Area under the curve (AUC) is reported as follows: AUC (95% confidence interval). Predictors were: baseline DAS28 >5.1, baseline HAQ >0.6, ABCB1 genotype, ABCC3 genotype, baseline erythrocyte folate, BMI >25kg/ m2 and current smoking. Table 2 Validation of multivariable logistic regressionmodels for insufficient response to MTX (DAS28>3.2) at 3months of treatment in an external validation cohort (U-Act-Early). tREACH derivation cohort N= 173 U-Act-Earlyvalidation cohort N= 91 Predictors OR (95%CI) OR (95%CI) DAS28 >5.1 3.7 (1.62 – 8.38)** 4.1 (1.44 – 11.82)** HAQ >0.6 2.8 (1.15 – 7.00)* 2.1 (0.67 – 6.35) ABCB1 GG/GA 2.4 (1.06 – 5.23)* 1.0 (0.37 – 2.75) ABCC3 TC/CC 3.1 (1.39 – 6.94)** 0.6 (0.23 – 1.79) Folate <750 nmol/L 2.1 (0.97 – 4.40) 3.4 (0.88 – 12.79) Smoker 4.2 (1.91 – 9.42)** 1.3 (0.44 – 4.00) BMI >25 kg/m 2 3.3 (1.52 – 7.21)** 1.6 (0.62 – 4.23) AUC (95%CI) 0.81 (0.74 – 0.87) 0.75 (0.64 – 0.85) Left column presents data from the derivation cohort (tREACH) and right of the external validation cohort (U-Act-Early). Predictors that contributed significantly to the model were indicated with an asterisk, where *P<0.05 and **P<0.01. OR= odds ratio; CI= confidence interval.