Patent ID: 8275850

Claim:
A method for assembling a longitudinally-linked database from individual patient healthcare transaction data records, the method comprising: at a central facility (LDF), receiving data records including at least one patient non-identifying attribute and at least one individually encrypted patient-identifying attribute, the at least one patient-identifying attribute first encrypted using a first encryption key specific to the LDF and further encrypted with a second encryption key unique to a data source so that original unencrypted patient identification information in the at least one patient-identifying attribute remains secret with respect to other data sources; partially decrypting the received data records using a decryption key complementary to the second encryption key so that the at least one patient-identifying attribute retains only the encryption by the first encryption key specific to the LDF; using an attribute-matching algorithm to assign an LDF identifier (ID) to the encrypted data records; and linking the encrypted data records ID by ID, whereby the longitudinally-linked data base is formed.