Table 3. Cox proportional hazard model of risk factors for cardiac involvement according to baseline variables.
| Variables | Model 1 | Model 2 | Model 3 | ||||||
|---|---|---|---|---|---|---|---|---|---|
| HR | 95% CI | P value | HR | 95% CI | P value | HR | 95% CI | P value | |
| Gender, ref: women | 8.103 | 2.124–30.909 | 0.002 | 7.898 | 1.574–39.639 | 0.012 | 21.683 | 2.899–162.196 | 0.003 |
| Age, yr | 1.024 | 0.969–1.081 | 0.402 | 1.043 | 0.978–1.112 | 0.199 | 1.124 | 1.006–1.256 | 0.039 |
| Anti-Sm antibody, ref: negative | 6.211 | 1.545–24.974 | 0.010 | 10.219 | 1.931–54.090 | 0.006 | 17.746 | 2.132–147.675 | 0.008 |
| Anti-Ro antibody, ref: negative | 0.182 | 0.041–0.796 | 0.024 | 0.181 | 0.037–0.889 | 0.035 | 0.367 | 0.065–2.079 | 0.257 |
| SDI, ref: SDI = 0 | 5.238 | 1.280–21.426 | 0.021 | 4.966 | 1.091–22.602 | 0.038 | 6.444 | 1.068–38.873 | 0.042 |
| Smoking, ref: non-smoking | 1.104 | 0.115–10.622 | 0.932 | 0.329 | 0.016–6.657 | 0.469 | |||
| BMI, ref: normal | 0.639 | 0.142–2.877 | 0.560 | 0.342 | 0.047–2.507 | 0.291 | |||
| Hypertension, ref: absence | 1.538 | 0.314 –7.540 | 0.595 | 1.487 | 0.211–10.495 | 0.691 | |||
| Hyperlipidemia, ref: absence | 0.476 | 0.050–4.497 | 0.517 | 0.171 | 0.007–4.364 | 0.285 | |||
| Diabetes mellitus, ref: absence | 2.473 | 0.487–12.547 | 0.275 | 1.492 | 0.214–10.495 | 0.686 | |||
| Renal involvement, ref: absence | 2.304 | 0.607–8.744 | 0.220 | 2.492 | 0.413–15.046 | 0.319 | |||
| SELENA-SLEDAI | 0.959 | 0.780–1.178 | 0.687 | ||||||
| Anti-dsDNA antibody, ref: negative | 6.123 | 0.560–66.908 | 0.137 | ||||||
| Complement 3, mg/mL | 1.004 | 0.951–1.060 | 0.882 | ||||||
| Complement 4, mg/mL | 1.006 | 0.904–1.120 | 0.908 | ||||||
| Corticosteroid dose, mg/day | 1.112 | 1.001–1.234 | 0.047 | ||||||
| Hydroxychloroquine dose, mg/day | 0.996 | 0.985–1.007 | 0.426 | ||||||
BMI = body mass index, SELENA-SLEDAI = safety of estrogen in lupus erythematosus national assessment-systemic lupus erythematosus disease activity index, SDI = Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index, HR = hazard ratio, CI = confidence interval.