Pharmaceutical Statistics Using SAS

13.1. Introduction

Adequate clinical trials require the use of valid and reliable measurements. In general, a measure is said to be valid if it accurately reflects the concept it is intended to measure. A measure is said to be reliable if repeated assessments of a stable subject or population using the measure produces similar results. The establishment of the reliability and validity of a measure is not a single test, rather a summary of its psychometric properties using multiple approaches.

Section 2.2.2 of the ICH E9 guidelines emphasizes the importance of utilizing primary measures that are both reliable and valid for the population enrolled in a clinical trial. Specifically, "there should be sufficient evidence that the primary variable ...