Table 2.
Multivariate models predicting new carotid plaque formation in nondiabetic patients with rheumatoid arthritis over 3.6 ± 0.2 yearsa
| New carotid plaque formation during follow-up (yes vs no) | |||
|---|---|---|---|
| Parameters | β coefficient | P value | Odds ratio (95% CI) |
| Model 1: traditional CV risk factors (r2 = 0.0453) | |||
| Age at follow-up end (years) | 0.146 | 0.004 | 5.752b (1.770 to 18.694) |
| Sex | 0.038 | 0.970 | 0.963b (0.134 to 6.927) |
| Total years of smoking (at follow-up end) | 0.051 | 0.023 | 2.628b (1.145 to 6.029) |
| SBP AUC (mmHg × months) | 0.001 | 0.346 | 1.495b (0.648 to 3.449) |
| LDL AUC (mg/dl × months) | 0.000 | 0.126 | 0.507b (0.212 to 1.211) |
| BMI (at follow-up end) | 0.088 | 0.356 | 1.445b (0.661 to 3.160) |
| Model 3 RA treatment (months of treatment during follow-up) (r2 = 0.248) | |||
| Corticosteroids | 0.067 | 0.016 | 3.058 (1.231 to 7.593) |
| Biologic agents | -0.035 | 0.046 | 0.502 (0.255 to 0.987) |
| Nonbiologic DMARDs | -0.017 | 0.477 | 0.802 (0.437 to 1.473) |
| Final model (r2 = 0.559)c | |||
| Age at follow-up end (years) | 0.136 | 0.006 | 5.098 (1.599 to 16.250) |
| Total years of smoking (at follow-up end) | 0.055 | 0.009 | 2.875 (1.305 to 6.335) |
| Corticosteroids (months during follow-up) | 0.086 | 0.016 | 4.170 (1.299 to 13.385) |
| Biologic agents (months during follow-up) | -0.033 | 0.118 | 0.520 (0.230 to 1.180) |
aAUC: area under the curve, BMI: body mass index, CV: cardiovascular, DMARDs: disease modifying antirheumatic drugs, LDL: low-density lipoprotein, RA: rheumatoid arthritis, SBP: systolic blood pressure. cOnly the variables from models 1 to 3 that predicted new plaque formation were used in the final model. Model 2 is described in the text only. bThe odds ratio for the continuous values was assessed for 1 SD increase and so is provided by exp(β*SD) (SD for age 12.0, for total years of smoking 19.15, for SBP (AUC) 629.10, for LDL (AUC) 1343.77, for BMI 4.25, for corticosteroid treatment (months during follow-up) 16.60, for biologic agents received (months during follow-up) 19.90, for nonbiologic DMARDs (months during follow-up) 13.20). Dependent variable 0 is subjects with no new plaque (n = 45), variable 1 is subjects with at least one plaque (n = 19) at the end of follow-up (binary logistic regression analysis using enter method is presented, and identical results in all models were obtained using the backward method).