The period of time defined in the Study Protocol, usually before administration of Investigational Product(s), during which assessments are made which then serve as reference for subsequent assessments in the study.
Blind/ Blinding
To avoid bias the majority of trials are carried out in a 'blind' manner. There are 2 common types of blinding: Single blind where the subject does not know which treatment they have been given. Double blind - where neither the subject nor the Investigator knows which treatment has been given.
