Study outcome measurement
For clinical trials, a study outcome measurement refers to a planned measurement that is used to determine the effect of a therapy on participants. For observational studies, a study outcome measure is a planned measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or therapies. Types of outcome measures include primary outcome measure, secondary outcome measure, and exploratory outcome measure.
To avoid bias, study outcome measures are required to be planned prior to the beginning of a study and included in the study protocol. In other words, the investigators must define what therapeutic effect of the therapy they are going to study and how they are going to measure that effect at the beginning of a study to make certain the approved study design fits that goal. Secondary and exploratory outcome measures may be included in the protocol but cannot replace the primary outcome measure(s) in the marketing approval process.