Selection bias can, and does, occur, even in randomized clinical trials. Steps need to be taken in order to ensure that this does not compromise the integrity of clinical trials; hence "Selection Bias and Covariate Imbalances in Randomized Clinical Trials" offers a comprehensive treatment of the subject and the methodology involved. This book: * Provides an overview of the hierarchy of study designs, and justifies the position of randomised trials at the top of this hierarchy. * Discusses the strengths and defects of randomisation, and provides real evidence to justify concern regarding its defects. * Outlays the damaging consequences that selection bias causes when it does occur. * Considers courses of action that can