Table 3. Fine and gray regression analysis seeking risk factors for developing secondary myelofibrosis (N = 87).
| Variables | Univariate analysis | Multivariate analysis | ||||
|---|---|---|---|---|---|---|
| HR | 95% CI | P | HR | 95% CI | P | |
| Age > 60 yr | 1.16 | 0.29–4.69 | 0.831 | - | - | - |
| Male | 0.42 | 0.10–1.72 | 0.228 | - | - | - |
| Degree of splenomegalya | 5.23 | 1.44–18.99 | 0.012 | 7.75 | 1.87–32.10 | 0.005 |
| WBC > 12.0 ×109/L | 1.31 | 0.29–5.86 | 0.723 | - | - | - |
| Monocyte > 1.0 ×109/L | 2.57 | 0.49–12.39 | 0.263 | - | - | - |
| Platelet > 1,000 ×109/L | 0.05 | 0.00–44.71 | 0.813 | - | - | - |
| LDH > 1.5 ×UNL | 3.79 | 0.75–12.24 | 0.108 | - | - | - |
| JAK2V617F VAF > 50%b | 1.82 | 0.11–29.12 | 0.672 | - | - | - |
| JAK2V617F VAF > 70%b | 4.64 | 0.29–74.23 | 0.278 | - | - | - |
| Positive JAK2 exon12 mutation | 0.04 | 0.00–1.03 | 0.637 | - | - | - |
| Abnormal karyotype | 44.55 | 2.67–742.55 | 0.008 | 261.48 | 7.57–9.036.32 | 0.002 |
| Hydroxyurea treatment | 26.69 | 0.05–15.44 × 103 | 0.457 | - | - | - |
| Thrombosis before or at diagnosis | 3.35 | 0.53–21.01 | 0.197 | - | - | - |
HR = hazard ratio, CI = confidence interval, WBC = white blood cell, LDH = lactate dehydrogenase, UNL = upper normal limit, VAF = variant allele frequency.
aNo splenomegaly, volumetric splenomegaly, and palpable splenomegaly; bA total of 61 patients were examined.