Study design and experimental methodology

Chapter 3 introduced the central topic of research questions in clinical trials. It also introduced the null and alternate hypotheses. This chapter discusses the relationship between research questions and study design, and shows how optimum experimental methodology is critical to the successful implementation of studies conducted to answer research questions. 

Each study in a clinical development program addresses one or more research questions (we noted in the previous chapter that it is a good idea to limit the number of research questions in any given trial). In Chapter 3 we also noted two characteristics that a research question must possess to be considered useful  

A useful research question suggests how a study needs to be designed to provide the appropriate information to answer the question. Choosing the best study design to answer the research question is therefore critical. The word 

This chapter also discusses experimental methodology. As well as employing the best study design to facilitate the collection of data to answer a research question most appropriately 

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Chapters 3 and 4 discuss how research questions are asked and answered in statistical language during clinical trials, and introduce the study designs and experimental methodologies that are used to acquire optimum quality data with which to answer our research questions. Chapter 5 discusses statistical ways of describing and summarizing these data. Chapter 6... 

In the following book chapter [118] the last 10 years of research on (thio)urea organocatalysts are summarized considering catalyst design concepts, experimental details such as structure optimization studies, screening conditions, reaction conditions, the typical substrate and product spectrum of each procedure as well as proposed mechanistic scenarios for each published methodology (-150 articles). 

This book, which focuses on biological considerations in clinical trials, is written very much in this spirit. While study design, experimental methodology, and statistical analysis are central characters in our discussions of new drug development, their importance lies in their role in the development of drugs that influence a patient s biology for the better. 

There are two components to evidence-based medicine and two related sets of responsibilities. The first component is clinical research. Clinical research is a scientific endeavor that provides evidence concerning potential therapeutic interventions. This book has focused on one particular therapeutic intervention, drug therapy. Once clinical trials have been conducted, the evidence obtained is published in clinical communications in journals. Everyone involved in clinical research has the responsibility to provide the best possible evidence in this manner. As noted throughout the book, this includes all aspects of clinical research study design, experimental methodology and clinical operations, analysis and interpretation, and also accurate and complete representation of study findings in clinical communications as discussed in Section 13.6. 

If forced to summarize the purposes of study design, experimental methodology, and statistical analysis in one sentence each, the following might be suitable ... 

Table 9 presents a comparison of basic epidemiological study designs for assessing child health outcomes by their inherent methodological strengths and limitations. While experimental study designs are included for completeness, none is appropriate for the evaluation of environmental influences on children s health when the exposure(s) cannot be randomized within acceptable research practices. 

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