- Documentation of all study relevant source data of every study participant will be done by completing the study specific electronic case report forms (eCRF, SoSci Survey) and study specific case report forms on paper (Adverse Events, Serious Adverse Events and concomitant medication). Data in the eCRF can be validated for completeness and discrepancies automatically. An audit trail system maintains a record of initial entries and changes (reasons for changes, time and date of changes, user identification of entry and changes).