Predicting recovery of the platelet count post chemotherapy

This graph indicates the ability of two different measurements of "reticulated" platelets to predict spontaneous recovery of platelet counts following chemotherapy. The two measurements shown are percent reticulated platelets (x-axis) and the mean fluorescence of reticulated platelets (platelet maturation index, y-axis). Patients with at least a 20,000/microL increase in platelet count over the ensuing 48 hours without platelet transfusion are shown as closed red circles, while those not showing spontaneous recovery within this time period are shown as open blue circles. When both parameters were normal or low (ie, data points falling within the box outlined with dashes) spontaneous recovery within the next 48 hours was not seen, with a negative predictive value of 91 percent. When one or both parameters were increased (ie, data points falling outside of the box), recovery within 48 hours was predicted with a postive predictive value of 82 percent.