This study investigates the survival outcomes of patients with certain blood disorders who are likely or unlikely to find a matched unrelated donor (MUD) for a transplant. The conditions include acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), myelodysplastic syndromes (MDS), non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), aplastic anemia (AA), …