Which term represents the guidelines governing when and how dates can be moved in duplicate patient histories?

• A. Date shifting policy
• B. Principles of date sliding
• C. Timeline movement rules
• D. Chronology adjustment standards

Answer: (B)

Date sliding is a privacy-preserving approach used in de-identified patient histories to move dates while keeping the sequence and timing of events meaningful. The idea behind the guidelines is to protect patient privacy by obfuscating exact dates, but still allow analysis that relies on temporal relationships within a record. The set of rules—often described as the Principles of date sliding—specifies how and when dates can be shifted, such as applying a consistent, random offset for each patient so that all dates for that patient move together, preserving the order and intervals between events. This enables meaningful longitudinal analysis without revealing actual calendar dates. For example, if a patient had events on January 1, January 5, and January 20, applying a fixed offset of 60 days would relocate them to March 2, March 6, and March 20, keeping the time gaps intact. In duplicates or multiple histories, applying the same offset to all records for a given patient ensures consistency across copies. This is why the best term is the Principles of date sliding—the phrase captures the governing guidelines for how dates can be moved.