Sequential Predictions Under Repeated Interventions: Estimating the Risk of Major Bleeding or Death With and Without Prophylactic Platelet Transfusion in Thrombocytopenic Neonates.

Preterm neonates often receive platelet transfusions when their platelet count is low to prevent bleeding. However, it is currently unclear which infants benefit from such transfusions. A recent randomized controlled trial (PlaNeT-2/MATISSE trial) showed that the higher platelet count threshold for transfusion was associated with a higher risk of major bleeding or death. Current transfusion protocols are based only on platelet count thresholds. However, neonates with similar platelet counts may have different bleeding risks due to varying clinical conditions. There is an important unmet medical need to identify which neonates with low platelet counts (i.e., severe thrombocytopenia) will benefit from a transfusion. Ideally, clinicians would be able to repeatedly predict a neonate's risk of major bleeding or death with and without giving a platelet transfusion, taking into account the neonate's clinical condition at that particular time. Obtaining personalized risk estimates under specific treatment strategies, with updated predictions at each new treatment decision moment, is called 'sequential prediction under interventions'. The investigators set up an international multicenter observational cohort study to develop a model to predict major bleeding or death with and without platelet transfusion at any time point during the first week after the onset of severe thrombocytopenia. This model is designed to support platelet transfusion decisions in the NICU and may help clinicians balance the benefits and harms of platelet transfusion based on updated characteristics of the neonate at the time of prediction.