. Author manuscript; available in PMC: 2010 Sep 1.

Published in final edited form as: Exp Hematol. 2009 Jun 24;37(9):1016–1021. doi: 10.1016/j.exphem.2009.06.006

TABLE 3.

Multivariable analyses for the prediction of thrombosis in follow-up

At diagnosis	HR	95% (CI)	p
Disease (PV vs ET)	1.55	1.02 – 2.36	0.04
Standard risk factors^*	1.89	1.34 – 2.66	0.001
JAK2^V617F (1–25%)	0.98	0.46 – 1.63	0.73
JAK2^V617F (26–50%)	1.12	0.79 – 1.87	0.56
JAK2^V617F (>50%)	1.19	0.81 – 2.01	0.52
WBC 7.5 – 9.1 (× 10⁹/L) ^†	1.52	0.88 – 2.61	0.13
WBC 9.1 – 11.3 (× 10⁹/L) ^†	1.67	0.92 – 2.70	0.09
WBC ≥ 11.3 (× 10⁹/L) ^†	1.93	1.01 – 2.77	0.04
*At 5 years from diagnosis*

Disease (PV vs ET)	1.54	0.80 – 2.97	0.19
Standard risk factors^*	1.19	0.71 – 2.01	0.51
JAK2^V617F (1–25%)	1.61	0.75 – 3.44	0.22
JAK2^V617F (26–50%)	1.74	1.00 – 3.50	0.01
JAK2^V617F (>50%)	2.89	1.47 – 5.61	0.002

Aged 60 years or older and/or previous thrombosis

Reference categories: ET, age below 60 years and asymptomatic, JAK2 wild type, WBC less than 7.5 (× 10⁹/L).

^†

Quartiles of the WBC count distribution at diagnosis used as cut-off; multivariable model using the PVSG cut-off for leukocytosis at 10 ×10^9/L produced an HR of 1.826 with 95% confidence interval 1.065–3.133 (p=0.0287)