title: Effect of investigator bias on the power and level of the two-sample Z-test.
abstract: The use of subjective measures in the evaluation of treatment efficacy in clinical trials may introduce bias into the response variables of interest when investigators attempt to guess the treatment that patients are receiving. The bias may be introduced even in the setting of double-blind clinical trials due to the presence of characteristic side effects. The introduction of bias leads to an increase in the power of the statistical test. However, this increase in power is achieved at a considerable increase in the actual level of the statistical test.
authors.affiliation: Merck & Co., Inc., Horsham, Pennsylvania 19044, USA.
authors.forename: P
authors.initials: P
authors.lastname: DeLucca
authors.forename: D
authors.initials: D
authors.lastname: Raghavarao
authors.forename: S
authors.initials: S
authors.lastname: Altan
mesh_terms: D004311:Double-Blind Method; D006801:Humans; D008432:Mathematical Computing; D015233:Models, Statistical; D015588:Observer Variation; D010919:Placebos; D016032:Randomized Controlled Trials as Topic / Q000379:methods* / Q000706:statistics & numerical data*
chemical_list: D010919:Placebos