title: Decision-making in familial database searching: KI alone or not alone?
abstract: We consider the comparison of hypotheses "parent-child" or "full siblings" against the alternative of "unrelated" for pairs of individuals for whom DNA profiles are available. This is a situation that occurs repeatedly in familial database searching. A decision rule that uses both the kinship index (KI), also known as the likelihood ratio, and the identity-by-state statistic (IBS) was advocated in a recent report as superior to the use of KI alone. Such proposal appears to conflict with the Neyman-Pearson Lemma of statistics, which states that the likelihood ratio alone provides the most powerful criterion for distinguishing between any two simple hypotheses. We therefore performed a simulation study that was two orders of magnitude larger than in the previous report, and our results corroborate the theoretical expectation that KI alone provides a better decision rule than KI combined with IBS.
authors: Institute of Genetics, University College London, Gower Street, London WC1E 6BT, UK. d.balding@ucl.ac.uk
authors: David J
authors: DJ
authors: Balding
authors: Michael
authors: M
authors: Krawczak
authors: John S
authors: JS
authors: Buckleton
authors: James M
authors: JM
authors: Curran
mesh_terms: D030541:Databases, Genetic; D003657:Decision Making; D005190:Family / Q000523:psychology*; D006801:Humans; D016247:Information Storage and Retrieval