6B-03 - Linkage of Electronic Health Record Data Across Two Healthcare Systems for Perinatal Health Research: A Privacy-Preserving Approach

Background: institutions. In the United States, birthing parent-infant dyads may receive care from multiple healthcare systems. Linkage of an individual’s electronic health records (EHR) across healthcare systems, in addition to birthing parent-infant linkage, may be necessary to obtain appropriate clinical data for perinatal health research.

Objectives: To develop a privacy-preserving process to link the health records of patients shared by two health systems for a perinatal health study, and to assess data enhancements associated with the linkage.

Methods: We included pregnant patients who received care from at least one of two healthcare systems based in Minnesota, USA and their infants born between December 2020 and September 2022 who had at least one well visit. We identified infants from one health system with birthing parents who potentially received care in the second health system based on the infant’s delivery hospital. Using the Health Insurance Portability and Accountability Act (HIPAA) Privacy Act-compliant Secure Hash Algorithm 256 bits (SHA256), we implemented a one-way matching process. Specifically, we used four hash ID rules based on six identifiers available in the EHR at both sites (infant birth date, birthing parent birth date, infant last name, infant zip code, delivery hospital name, and infant sex) plus a consistent salt. We applied study eligibility criteria to birthing parents of successfully matched infants. We reported characteristics of study-eligible parents according to whether they had data from the second system or only the first system.

Results: One health system identified 3,524 infants with birthing parents who potentially received care in the second system. The second system identified 39,321 infants delivered at the hospitals of interest during the study period. The algorithm matched 3,406 (96.7%) infant records. After applying study eligibility criteria, the birthing-parent records gained through hash matching increased the study population by 7.2% from 8,100 to 8,686. Overall, 13.6% of the study population had data from the second health system. Birthing parents with data from the second system compared with data only from the first system more often were non-Hispanic Black (25.0% vs 19.2%) and had public insurance during pregnancy (36.4% vs 18.2%). Furthermore, they were more likely to have multiple gestations (3.1% vs 1.5%) and were less likely to be primiparous (32.6% vs 43.6%).

Conclusions: The hash matching approach can increase study size, patient diversity, and data completeness in a privacy-preserving manner for perinatal health studies among patients that use multiple healthcare systems.