title: The how and why of "negative" research studies.
authors.forename: Duminda N
authors.initials: DN
authors.lastname: Wijeysundera
authors.forename: Rita
authors.initials: R
authors.lastname: Katznelson
mesh_terms: D053327:Apolipoprotein E4 / Q000235:genetics*; D001499:Bayes Theorem; D003072:Cognition Disorders / Q000209:etiology*; D016001:Confidence Intervals; D003693:Delirium / Q000209:etiology*; D005838:Genotype; D006801:Humans; D011183:Postoperative Complications / Q000209:etiology*
chemical_list: D053327:Apolipoprotein E4