Table 2.
Distribution of outcomes and hazard estimates per multivariable Cox proportional hazards modeling
| Thrombosis | Evolution | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Event rate | Median time to event (mo) | HR (95% CI)* | P | Overall P | Event rate | Median time to event (mo) | HR (95% CI)† | P | Overall P | |
| Leukocyte trajectory | ||||||||||
| WBC5 | 5/93 (5%) | 28.8 | Reference | 0.4163 | 3/94 (3%) | 72.2 | Reference | .0002 | ||
| WBC10 | 22/190 (12%) | 34.8 | 2.32 (0.86-6.27) | .0957 | — | 16/194 (8%) | 60.2 | 2.55 (0.73-8.89) | .1418 | — |
| WBC15 | 6/80 (8%) | 33.4 | 1.83 (0.54-6.21) | .3340 | — | 13/79 (16%) | 41.1 | 5.51 (1.55-19.58) | .0083 | — |
| WBC35 | 1/14 (7%) | 24.1 | 2.43 (0.26-22.35) | .4333 | — | 4/11 (36%) | 43.0 | 24.23 (5.03-116.83) | <.0001 | — |
| Overall | 34/377 (9%) | 31.9 | — | — | — | 35/378 (10%) | 55.2 | — | — | — |
| Hematocrit trajectory | ||||||||||
| HCT35 | 3/28 (11%) | 34.8 | 0.98 (0.23-4.13) | 0.9771 | .1849 | 1/21 (5%) | 60.2 | 0.53 (0.06-4.56) | .5634 | .5407 |
| HCT43 | 18/256 (7%) | 31.2 | 0.54 (0.25-1.19) | .1267 | — | 29/261 (11%) | 49.3 | 1.38 (0.56-3.43) | .4838 | — |
| HCT47 | 13/93 (14%) | 30.0 | Reference | — | — | 6/96 (6%) | 103.5 | Reference | — | — |
| Overall | 34/377 (9%) | 31.9 | — | — | — | 35/378 (10%) | 55.2 | — | — | — |
| Platelet trajectory | ||||||||||
| PLT125 | 3/32 (9%) | 26.6 | Reference | .9501 | 4/23 (17%) | 36.8 | Reference | .1670 | ||
| PLT300 | 15/159 (9%) | 34.5 | 0.82 (0.24-2.89) | .7629 | — | 12/158 (8%) | 48.2 | 0.45 (0.15-1.39) | .1646 | — |
| PLT600 | 16/186 (9%) | 37.0 | 0.89 (0.25-3.12) | .8532 | — | 19/198 (10%) | 61.8 | 0.34 (0.11-1.04) | .0592 | — |
| Overall | 34/377 (9%) | 31.9 | — | — | — | 35/378 (10%) | 55.2 | — | — | — |
Multivariable hazard ratio (HR) adjusted for age at diagnosis, sex, duration of disease at time of institutional contact, sum of cardiovascular risk factors (diabetes, hypertension, hyperlipidemia, coronary artery disease, and smoking), and whether the patient was receiving cytoreductive therapy (hydroxyurea, peg-IFN-α, or ruxolitinib) at some point during the landmark trajectory-modeling period.
Multivariable HR adjusted for age at diagnosis, duration of disease before institutional contact, and whether the patient was receiving cytoreductive therapy (hydroxyurea, peg-IFN-α, or ruxolitinib) at some point during the landmark trajectory-modeling period.