The aim of record-keeping and handling of data is to gather information from the study without error in a form that can later be analysed and reported. The investigator and monitor must ensure that the data are of the highest possible quality at the point of collection. A case report form (CRF) for each patient in the study must be completed and signed by the investigator and assessor. The CRF is designed to record data on each trial subject during the course of the trial, as defined by the protocol. The data should be collected by procedures which guarantee preservation, retention and retrieval of information, and allow easy access for verification and audit. The patient’s files, CRFs and other sources of primary data must be kept for future reference. Patient data must be handled in a way that maintains confidentiality and yet ensures accuracy. The condition of the patient before treatment, and the response to the treatment, including the observations of the assessor, the feelings of the patient and possible adverse effects, need to be fully documented. All efforts should be made to maintain error-free records.

When subjects are randomized to different groups, the randomization procedure used must be documented.