Table 6.
Fine and Gray regression analysis to determine risk factors for developing myelofibrosis in patients with polycythemia vera (N=131).
| Univariate analysis | Multivariate analysis | ||||||
|---|---|---|---|---|---|---|---|
| HR | 95% CI | P | HR | 95% CI | P | ||
| Factors at diagnosis | |||||||
| Age >60 yr | 0.84 | 0.27–2.63 | 0.765 | - | - | - | |
| Female | 2.92 | 0.99–8.57 | 0.051 | - | - | - | |
| Palpable splenomegaly | 3.19 | 0.97–10.44 | 0.056 | - | - | - | |
| WBC >11.0×109/L | 1.44 | 0.38–5.44 | 0.588 | - | - | ||
| Monocyte >1.0×109/L | 3.17 | 0.89–11.35 | 0.076 | - | - | - | |
| Platelet >1,000×109/L | 2.01 | 0.30–13.68 | 0.473 | - | - | - | |
| LDH >1.5×UNL | 4.01 | 1.04–15.59 | 0.044 | 2.39 | 0.31–18.60 | 0.405 | |
| Positive JAK2V617F | 2.72 | 0.30–24.40 | 0.386 | - | - | - | |
| Positive JAK2 exon 12 mutation | 2.67 | 0.35–20.16 | 0.341 | - | - | - | |
| Abnormal karyotype | 21.44 | 5.71–80.91 | <0.001 | 18.20 | 2.0–165.95 | 0.010 | |
| Thrombosis before or at diagnosis | 0.31 | 0.04–2.63 | 0.284 | - | - | - | |
| Hydroxyurea treatment | 2.20 | 0.27–17.74 | 0.458 | - | - | - | |
Abbreviations: CI, confidence interval; HR, hazard ratio; LDH, lactate dehydrogenase; UNL, upper normal limit.