Elysium Next Generation Master Patient Index (MPI) Scott Parkey Research Engineer © Axolotl Corp. 2010

Introduction Founded in 1995, Axolotl provides Health Information Exchange (HIE) products and services to the RHIO and hospital system markets. Axolotl’s Elysium® Exchange solutions are used by more than 25,000 physicians, 80,000 healthcare professionals, 200 hospitals, 3 Statewide HIEs and 18 RHIOs - touching the lives of more than 25 million patients.

HIE in 60 seconds Facilitate the exchange of health information between: Hospital EMR systems Emergency departments Provider offices Labs Pharmacies Imaging facilities Public health agencies Payers (mostly for eligibility checks)

Patient Matching in a HIE We integrate a wide variety of – software (EMR, PHR, lab, pharmacy, biosurveillance, etc.) – underlying data models – data exchange formats There may be some trusted, shared identifiers between existing systems, but these are uncommon.

New MPI Goals Updated technology: improve performance, scalability, availability, automate maintenance Maintain full RIM fidelity in demographic records Fully implement the HL7v3 patient / person classes and IHE’s PIX / PDQ profiles Probabilistic scoring Support for advanced matching options (name morphology, edit distance) Allow for finer-grained configuration of search and matching rules

Implementation Direct storage and manipulation of CDA fragments (patient demographics only) in DB2 pureXML – Native, efficient tree-based XML representation – XML indexing by XPath – Adheres to the SQLXML standard Matching algorithm – Pre-filter – Score – Evaluation

Implementation Custom HL7v3 Java library – Constructing CDA fragments from Java objects – Constructing Java objects from CDA fragments for matching algorithms Simple RIM-based configuration

Use of RIM / CDA Patient Data (XML in DB2) John Public … Match Score Configuration Data ElementMatchTypePositiveNegativeNoResult /ClinicalDocument/…/patient/name/givenEquals Prefilter Query (pseudo-code) select * from MPI.PATIENT_DATA where XMLEXISTS(‘… $PATIENTDATA/ClinicalDocument/recordTarg et/patientRole/patient[name/given=$given and [OR …]

Patient 3 Data …. John Q Public … Patient Database Patient 1 Patient 2 Patient 3 Patient 4 Patient 5 Patient 6 Patient 7

Family name: Public? Patient Database Patient 1 Patient 2 Patient 3 Patient 4 Patient 5 Patient 6 Patient 7 xquery/SQLXML Prefiltered results Patient 3 Patient 6 Patient 7

Family name: Public? Match score Patient 35 Patient 63 Patient 71 Patient 3 Data …. John Q Public …

IHE Profiles MPI will be able to form the basis of IHE profile implementations PDQ – Matching queries to records PIX – Cross-referencing different records – ID correlation: send ID, return matching IDs More

Questions?