Event graphs for the 3 patients with grade 4 bleeds showing the patients' daily platelet counts (Δ) and the dose of platelets transfused during their thrombocytopenia periods. Solid lines represent prophylactic platelet transfusions and dashed lines indicate therapeutic platelet transfusions. When 2 platelet transfusions were given on the same day, the additive dose is plotted and a “2” is depicted at the top of the line.