Abstract: A longitudinal database of de-identified patient healthcare transaction data records linked by longitudinal linking tags (IDs) is provided. A new healthcare transaction data record, which may include alphanumeric identification code attributes, third party attributes and/or demographic attributes, is assigned an linking ID associated with a previous healthcare transaction data record based upon successful comparison of either a designated set of identification code attributes or a designated set of demographic attributes.

Abstract: A longitudinal database of de-identified patient healthcare transaction data records linked by longitudinal linking tags (IDs) is provided. A new healthcare transaction data record, which may include alphanumeric identification code attributes, third party attributes and/or demographic attributes, is assigned an linking ID associated with a previous healthcare transaction data record based upon successful comparison of either a designated set of identification code attributes or a designated set of demographic attributes.

Abstract: A method is provided for assigning longitudinal linking tags to de-identified patient data records by matching the patient data records with reference data records. The de-identified patient data records may include both encrypted and non-encrypted data attributes. Different possible subsets of the data attributes are categorized in a hierarchy of levels. Subsets of data field values are compared with the reference data records one level at a time. Upon successful comparison or matching of a subset of data field values, a longitudinal linking tag associated with a matched reference data record is assigned to de-identified data record is assigned. When a match is not found, a new longitudinal linking tag is created and assigned to the de-identified data record. The new tag and corresponding data record attributes are then added to the reference data for future matching operations.