Another way to avoid false-positives is to demand replication of the original study, with the repeat experiment carried out in entirely different circumstances, but with essentially the same protocol. For new pharmaceuticals to be approved by the US Food and Drug Administration, it has become standard that two independent clinical trials must have been carried out, each showing clinical benefit that is significant at P < 0.05. This means that the overall chance of approving a drug, that in truth has no benefit at all, is 0.05 × 0.05 = 0.0025, or 1 in 400.
Double clinical trial
