January 16, 2022
De-identification methods for data exporting
REDCap provides advanced de-identification options that can be optionally used when exporting data, such as removing known Identifier fields, removing invalidated text fields, notes fields, or date fields, date shifting and hashing of the record names. These options provide greater security and data protection when a user is exporting sensitive data out of REDCap.
Date shifting: As part of the de-identification options in REDCap, all dates in the database may be shifted so that they do not reflect the actual dates. If the option to have all dates shifted is chosen, they will be shifted by a consistent length of time for each record, thus preserving the interval between dates. Date shifting leaves the database record intact and will not affect the actual saved dates in the database. The shifted dates will always be the same for each record when performing a data export. The dates are shifted back in time up to 364 days, in which the shifted value is based on the Study ID using a complex algorithm. Because the shifted value is based on the record name, the amount that dates are shifted is unique for each record, but the shifted amount remains the same within each record to maintain internal consistency. Date shifting prevents any dates from being used as identifiers for each database record while preserving the interval between dates.