Chapter 5

Conducting Clinical Research

IN THIS CHAPTER

Planning and carrying out an experimental clinical trial study

Protecting the participants

Collecting, validating, and analyzing research data

This chapter provides a closer look at a special kind of human research — the clinical trial. The

purpose of a clinical trial is to test one or more interventions, such as a medication or other product or

action thought to be therapeutic (such as drinking green tea or exercising). One of the important

features of a clinical trial is that it is an experimental study design, meaning that participants in the

study are assigned by the study staff which intervention to take. Therefore, there are serious ethical

considerations around clinical trials. On the other hand, the clinical trial study design provides the

highest quality evidence you can obtain to determine whether or not an intervention actually works,

which is a form of causal inference. In this chapter, we cover approaches to designing and executing a

high-quality clinical trial and explain the ethical considerations that go along with this.

Designing a Clinical Trial

Clinical trials should conform to the highest standards of scientific rigor, and that starts with the design

of the study. The following sections note some aspects of good experimental design.

Identifying aims, objectives, hypotheses, and variables

The aims or goals of a clinical trial are short general statements (often just one statement) of the

overall purpose of the experiment. For example, the aim of an experiment may be “to assess whether

drinking green tea every day improves alertness in older adults.”

The objectives are much more specific than the aims. In a clinical trial, the objectives usually refer to

the effect of the intervention (treatment being tested) on specific outcome variables at specific points

in time in a group of a specific type of study participants. In a drug trial, which is a type of

experimental clinical research, an efficacy study may have many individual efficacy objectives, as

well as one or two safety objectives, while a safety study may or may not have efficacy objectives.

When designing a clinical trial, you should identify one or two primary objectives — those

that are most directly related to the aim of the study. This makes it easier to determine whether the

intervention meets the objectives once your analysis is complete. You may then identify up to

several dozen secondary objectives, which may involve different variables or the same variables

at different time points or in different subsets of the study population. You may also list a set of