Linking patients' records across organizations while maintaining anonymity

In an health information exchange (HIE) project, linking patients' health records across organizations while maintaining appropriate patients anonymity is essential. Anonymous identifiers created from various combinations of personal identifiers using one way encryption function were evaluated for linkage quality between two synthesized databases. Preliminary results show that such anonymous identifiers (IDs) based on date of birth, zip code and last name or first name can link records with high specificity and sensitivity.