Table 3. Prediction model and scores for 3 months MTX non-response (DAS28>3.2).
| Predictors | β | Score | OR (95% CI) | p | |
|---|---|---|---|---|---|
| Baseline Das28 | >5.1 | 1.13 | 1 | 3.08 (1.26–7.52) | 0.014 |
| HAQ | >0.6 | 1.26 | 1 | 3.53 (1.30–9.56) | 0.013 |
| ABCB1 rs1045642 G>A | AA vs GG/GA | 1.34 | 1 | 3.82 (1.54–9.47) | 0.004 |
| ABCC3 rs4793665 T>C | TT vs TC/CC | 1.24 | 1 | 3.45 (1.44–8.31) | 0.006 |
| Folate in erythrocytes | <750 nmol/L | 0.82 | 1 | 2.28 (1.02–5.12) | 0.046 |
| Current Smoking | 1.75 | 2 | 5.77 (2.34–14.24) | <0.001 | |
| BMI | >25 kg/m2 | 1.11 | 1 | 3.02 (1.31–6.97) | 0.009 |
| Constant | -5.07 | * | 0.01 | ||
| AUC derivation cohort | 0.80 (0.73–0.86) | <0.001 | |||
| AUC validation cohort | 0.80 (0.69–0.91) | <0.001 | |||
| Hosmer-Lemeshow test | 0.816 |
Risk score of an RA patient having all predictors is calculated as follows: Add up scores of individual predictors, namely 1+1+1+1+1+2+1, which equals 8 points.
*The constant was suppressed.
MTX, methotrexate; DAS28, disease activity score in 28 joints; OR, odds ratio; CI, confidence interval; HAQ, health assessment questionnaire; ABCB1, adenosine triphosphate-binding cassette transporter B1; BMI, body mass index; AUC, area under the receiver operating characteristics curve.