Patient data requirements are established for each study according to scientific, regulatory, and reporting needs. Clinical trials data are entered to a central data base via generalized entry options whose names indicate the clinical or research category of the data, such as "Background", "Hematology", or "Toxicity".

Data may be entered only during the time period that the study is active, and only by users currently authorized . The central data base is maintained and documented by the System Coordinator. All data fields defined (or implied) by the protocol documents are supported upon request. All changes to the data base are compatible with existing data, and users are notified of changes via email, meetings, and/or memos.

The data dictionary supports valid values (look-up tables) and numeric range checking, as well as logic for cross-field or environment checking. Data are typically entered directly by care providers or from the patient chart without intermediary paper forms. The data base serves as the repository of "case report forms", from which various reports can be printed. Reports are generated for monitoring protocol activity, patient care, data analysis, and regulatory and sponsor reporting.