Association of circulating blasts with survival and distribution of bone marrow blasts. (A) Spline analysis of association of circulating blasts and hazard for death with 95% CI, showing increasing risk >7% circulating blasts and an exponential increase ≥10% circulating blasts. (B) Distribution of bone marrow (BM) blasts in chronic-phase vs accelerated-phase myelofibrosis. More patients in the accelerated-phase group had 5% to 9% or 10% to 19% bone marrow blasts before transplantation (P = .01). Distribution according to <5%, 5% to 9%, and 10% to 19% for accelerated-phase vs chronic-phase was 53% vs 86%, 20% vs 9%, and 27% vs 6%, respectively.