API Asian and Pacific Islander CBS Canadian Blood Services DEAP Distributed Evolutionary Algorithms in Python GA Genetic Algorithm HIS Hispanic HLA Human Leukocyte Antigens HPA Human Platelet Antigens NAM Native American/First Nation NMDP National Marrow Donor Program OTH Other PTR Platelet Transfusion Refractoriness 1 INTRODUCTION Platelet transfusion refractoriness (PTR) is defined as a poor increment in the platelet count post-transfusion.1 Patients exhibiting platelet refractoriness...