Abstract: One of the inventions relates a method for maintaining the contact information of an enrollee in a clinical study while maintaining the anonymity of the enrollee from the clinical study sponsor. The method includes: (1) obtaining contact information for the enrollee in the clinical study; (2) entering the contact information into a database; (3) using a contact cascade on a scheduled, periodic basis to contact the enrollee using the contact information from the database to ensure that the contact information is correct; and (4) updating the contact information if a contact is made with the enrollee and the contact information needs to be updated to be accurate.