Essential documentation such as personnel delegation and training logs should be completed along with any other necessary information for the trial to be able to commence recruitment at the site. Essential documents assist with the conduct of the study and trial master files should be established prior to the initiation of the study. ICH GCP provides a list of essential documents that you should maintain throughout the lifecycle of your study:

• Before the clinical phase of the trial commences,
• During the clinical conduct of the trial,
• After completion or termination of the trial

Essential documents will be inspected by regulatory authorities or other agencies to confirm the validity of the trial conduct and the integrity of the data. A final close-out of a study can only be done once all necessary essential documents are confirmed as filed.

If you use an electronic method of storage for essential documents, for example a Clinical Trial Management System, it is important that the system provides for document identification, version history, search, and retrieval.