Border Zones of Evidence: How Non-evidence Based Factors Influence Evidence Generation and Clinical Practice in Stroke Medicine.

The interpretation of the results of clinical trials should be done by examining the finer prints of extraneous factors such as stopping rules, interim analysis, intricacies of patient selection, and the rationale of decisions that lead to non-prespecified termination. This can be done only by critical education in the art and science of interpretation of evidence emerging from clinical trials. The pioneering pivotal studies, namely, NINDS rtPA and ECASS III trials, hold disproportionate influence in determining the contours of the subsequent fate of clinical trials and treatment guidelines. It needs to be recognized that the pooling of studies using dissimilar trial designs, notwithstanding similar patient profiles, would undermine the positive signal emerging from the studies that have used better selection methodologies to homogenize the study population.