How much do we have to pay for how many interim analyses?
From a methodological point of view, an enormous flexibility has been achieved with respect to the timing of interim analyses and the type I error alpha to be spend. Actual plans to spend alpha, however, are too often guided by the consideration of preserving as much alpha as possible for the final analysis. Practical consequences of spending tiny portions of alpha in many interim analyses are too often not appropriately acknowledged.
Koch
Armin
A
Biostatistics and Experimental Design, Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3 D-53175 Bonn, Germany. a.koch@bfarm.de
D002986:Clinical Trials as Topic / Q000379:methods / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D004341:Drug Evaluation / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D012107:Research Design