“PostStudy Anxiety” syndrome is our term for the feeling of ill-being at the end of a randomized clinical trial upon finding that the randomized groups differ to a disquieting degree with respect to one or more baseline characteristics. We discuss the meaning of such differences and argue that they are inevitable, not necessarily damaging the credibility of the study. We present an argument that “checking” the randomization is not a legitimate use of data collected at baseline. Further, we will present suggestions for steps that can be taken at the experimental design stage for dealing with important prognostic variables, whether unbalanced at baseline or note.
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