- If they are lost to follow-up. In all cases, the reason for and date of withdrawal must be recorded in the Exit Form and in the subject's medical records and the sponsor's representative must be notified within 5 days. The subject must be followed up to establish whether the reason was an adverse event, and, if so, this must be reported in accordance with the procedure of an adverse event (described bellow). The investigator must make every effort to contact subject lost to follow-up. Attempts to contact such subject must be documented in the subject's records (e.g., dates and times of attempted telephone contact).