A printed, optical, or electronic document designed to record all of the protocol-required information to be reported to the sponsor on each trial subject. NOTE: In common usage, CRF can refer to either a CRF page, which denotes a group of one or more data items linked together for collection and display, or a casebook, which includes the entire group of CRF pages on which a set of clinical study observations and other information can be or have been collected, or the information actually collected by completion of such CRF pages for a subject in a clinical study.
Source: ICH E6
