[Statistical insight to improve reliability of pharmacological studies]

When pharmaceutical scientists describe characteristics of a drug or when they decide whether it is appropriate to initiate clinical trials to determine the drug's effects in humans, their inferences are frequently grounded in information drawn from non-clinical studies. Therefore, certain and highly objective information is required. By introducing the concept of design of experiments to control some nuisance factors and performing confirmatory studies based on sample size estimation, trustworthy information can be efficiently obtained. This paper does not demand that researchers conduct an additional confirmatory study in a series of studies conducted so far. This is a reconsideration how a series of studies should be carried forward. Statistics ought to contribute much more not only to estimation or hypothetical tests after data are collected, but also to methodology of preliminary experiments and planning of studies. Cooperation with statisticians from an early stage of the studies is all the more helpful in non-clinical studies, in which, in a sense, "perfect" experiments can be conducted more than in clinical studies.