Risk factors for thrombosis in the follow-up: multivariable analyses considering covariates at diagnosis (baseline analysis) and before the vascular event (time-dependent analysis)
| Risk factors . | Baseline analysis . | Time-dependent analysis . | ||
|---|---|---|---|---|
| Hazard ratio (95% CI) . | P . | Hazard ratio (95% CI) . | P . | |
| Sex, male/female | 1.5 (0.8-2.9) | .1 | 1.4 (0.9-2.4) | .2 |
| Standard risk factors* | 2.3 (1.3-3.9) | .004 | 1.8 (1.1-3.0) | .04 |
| Hydroxyurea | ND | 0.5 (0.3-0.9) | .02 | |
| Antiplatelets | ND | 0.5 (0.3-0.9) | .02 | |
| WBC count of at least 8.7 × 109/L | 2.3 (1.4-3.9) | .001 | 1.6 (0.9-2.8) | .06 |
| HB of at least 14 g/dL | 0.5 (0.2-1.1) | .07 | 0.5 (0.2-1.1) | .07 |
| HCT of at least 42% | 1.2 (0.6-2.5) | .6 | 1.4 (0.7-3.1) | .4 |
| PLT of at least 784 × 109/L | 0.7 (0.4-1.1) | .1 | 0.9 (0.5-1.6) | .7 |
| Risk factors . | Baseline analysis . | Time-dependent analysis . | ||
|---|---|---|---|---|
| Hazard ratio (95% CI) . | P . | Hazard ratio (95% CI) . | P . | |
| Sex, male/female | 1.5 (0.8-2.9) | .1 | 1.4 (0.9-2.4) | .2 |
| Standard risk factors* | 2.3 (1.3-3.9) | .004 | 1.8 (1.1-3.0) | .04 |
| Hydroxyurea | ND | 0.5 (0.3-0.9) | .02 | |
| Antiplatelets | ND | 0.5 (0.3-0.9) | .02 | |
| WBC count of at least 8.7 × 109/L | 2.3 (1.4-3.9) | .001 | 1.6 (0.9-2.8) | .06 |
| HB of at least 14 g/dL | 0.5 (0.2-1.1) | .07 | 0.5 (0.2-1.1) | .07 |
| HCT of at least 42% | 1.2 (0.6-2.5) | .6 | 1.4 (0.7-3.1) | .4 |
| PLT of at least 784 × 109/L | 0.7 (0.4-1.1) | .1 | 0.9 (0.5-1.6) | .7 |
Cox proportional hazard models used for all calculations.
CI indicates confidence interval; and ND, not determined. All other abbreviations are explained in Table 1.
Aged 60 years or older and/or previous thrombosis.