title: The probability of finding suitable directed donors.
abstract: A series of tables based on mathematical calculations is given as guidelines for the number of directed donors needed by members of various ethnic/racial groups to provide a desired number of units of blood with a selected probability of achieving this result. From these tables, certain conclusions can be drawn. Unrelated donors who do not know their blood type are an inefficient source of directed donors. Rh-negative patients are unlikely to obtain enough directed-donor units from either related or unrelated donors with confidence unless these donors known their blood type. In general, siblings, parents, and offspring are the most efficient directed donors from the standpoint of compatibility. Cousins, uncles, aunts, nieces, and nephews are not much more likely to be compatible than unrelated donors are. It is easier to obtain suitable directed-donor units among Hispanics than among whites, blacks, or Asians, due to their skewed blood group frequencies. In general, using O-negative directed donors for Rh-positive recipients does not significantly increase the likelihood of finding suitable donors.
authors.affiliation: Department of Pathology, Southern California Permanente Medical Group, Los Angeles 90034.
authors.forename: M
authors.initials: M
authors.lastname: Kanter
authors.forename: S
authors.initials: S
authors.lastname: Selvin
authors.forename: B A
authors.initials: BA
authors.lastname: Myhre
mesh_terms: D001782:Blood Donors; D001787:Blood Group Incompatibility; D001788:Blood Grouping and Crossmatching; D006801:Humans; D011336:Probability