What Is the Question?

Abstract

The planning of a clinical trial depends on the question that the investigator is addressing. The general objective is usually obvious, but the specific question to be answered by the trial is often not stated well. Stating the question clearly and in advance encourages proper design. It also enhances the credibility of the findings. The reliability of clinical trial results derives in part from rigorous prospective definition of the hypothesis. This contrasts with observational studies where the analyses are often exploratory, may be part of an iterative process, and therefore more subject to chance [1]. One would like answers to a number of questions, but the study should be designed with only one major question in mind. This chapter discusses the selection of this primary question and appropriate ways of answering it. In addition, types of secondary and subsidiary questions are reviewed.