ABSTRACT
In clinical research, a quantitative instrument (or questionnaire) is often used to provide objective measurement of safety and efficacy of a test treatment under investigation across various therapeutic areas. In practice, although there exist many instruments such as Hamilton-D (Hamilton scale for depression) and Hamilton-A (Hamilton scale for anxiety) for central nervous system (CNS) and quality of life (QOL) assessment in cancer trials, the investigators frequently face the need to develop new ones. A typical example is the development of an objective instrument for evaluation of clinical benefits including safety, efficacy, and/or quality of life of traditional Chinese herbal medicines. This need arises because proper development/validation or modification of instruments can achieve specific purposes relative to specific target patient populations. While the existing instruments may include one that has been developed for the target patient population and the desired purpose, new research questions often require new instruments or modification of existing instruments for measurement. Validation of the developed instrument is important to ensure a proper sampling and a valid measurement of the content of the subjective state, behavior, or disease to be measured. In this chapter, without loss of generality and for illustrative purposes, we will focus on validation of a developed instrument for assessment of QOL in cancer trials. The performance characteristics for validation of QOL instruments can be applied to other instruments for other purposes such as the evaluation of safety and efficacy of TCMs across therapeutic areas.
