Chapter 6: Clinical (Therapeutic) Trials

INTRODUCTION

Where Have You Been?

Up to this point, you have learned how to find research that you could apply to your clients or patients. That has included finding the evidence using electronic databases and then applying it to your practice situation. You have also learned to evaluate different aspects of the research you find. Among those key elements are identifying the type of outcome used in the research and determining whether those outcomes meet your need. This includes identifying the performance aspect of the outcome or where on the disablement continuum each of the outcomes belongs; whether the outcome is patient based or clinician based, and whether it is disease oriented or patient oriented. For an outcome to be worthwhile, it must also meet technical requirements such as validity, reliability, responsiveness, and interpretability. You have also learned classic research designs frequently encountered in exercise science and rehabilitation research. Each of these designs has strengths and weaknesses that make them useful for particular circumstances. Furthermore, depending on the design and scope of the study, the study may or may not be internally valid for establishing cause and effect. You also learned that internal and external validity often oppose each other, and that research is often a compromise among competing goals.

Where Are You Going?

The previous chapters have focused on the basics of research. In this chapter, these concepts are extended to apply to true clinical research. You will learn that clinical research organizes research questions into a hierarchy, and the measures that were previously discussed fit within this hierarchy. Research designs in clinical research are either similar or identical to the designs you previously learned. However, they may go by a different name. Clinical trials may be described as occurring in phases. This is very common in pharmaceutical research, and these phases are described in the context of exercise science and rehabilitation research. You will also learn the importance of random assignment of research participants and how different methods of randomization work. Finally, you will learn how to calculate two clinical measures: numbers needed to treat and numbers needed to harm. These measures are useful in interpreting research and can be easily calculated with data presented in the clinical trials results if the authors have not done so.