Figure 1
Kaplan-Meier estimate of blast phase–free survival in primary myelofibrosis according to the DIPSS. Risk categories were according to the score obtained anytime during follow-up. Values for score calculation are as follows: 1 for age > 65 years, 2 for hemoglobin level < 10 g/dL, 1 for white blood cell count > 25 × 109/L, 1 for peripheral blood blasts ≥ 1%, and 1 for constitutional symptoms. Risk categories are low (score: 0), intermediate-1 (score: 1 or 2), intermediate-2 (score: 3 or 4), and high (score: 5 or 6).
