(275) Linkage of Mother and Infant Records using Commercial Claims Data within the Food and Drug Administration (FDA) Biologics Effectiveness and Safety (BEST) Initiative

Background: Linkage of real-world data (such as administrative claims data) on mothers and infants facilitates post-market safety surveillance of biologics, including vaccines, during pregnancy and following infants’ birth.

Objectives: To describe the linkage of individuals, who had a live birth, to their infants using commercial health claims databases, and to report the linkage rates overall, by maternal age group, gestational age at delivery, and U.S. care setting.

Methods: The mother-infant linkage was established in three commercial health insurance claims databases in the U.S.: CVS Health, 2018–2023; Optum, 2018–2023; and Carelon Research 2016–2023. Of females aged 12-55 years, we identified pregnancies that resulted in a live delivery at least one year following the start of data availability using a validated algorithm. Liveborn infants were then identified by having a birth date occurring at least one year following the first available date in the dataset. Mothers whose delivery dates occurred within three days of infants’ birth dates were then linked using the insurance subscriber ID. Linkage rates, defined as the proportion of deliveries that linked to an infant, were estimated overall, for each database, maternal age group, gestational age, and care setting during delivery.

Results: We identified 2,855,647 live birth deliveries and 2,953,714 live born infants with a known subscriber ID, and valid delivery dates and birth dates. Most live deliveries occurred in the hospital inpatient setting (range 91.6%-93.0% by database) and were full-term (range 86.2%-86.8% by database). The proportion of deliveries that linked to at least one infant, within 3 days, ranged from 70.7%-80.9% by database. The highest linkage rates were observed among mothers aged 30-49 years (range 81.1%-88.6%) and the lowest among mothers aged 12-24 years (range 25.8%-34.2%). Inpatient deliveries had the highest linkage rates (range 71.8%-82.5%), and emergency department deliveries had the lowest (range 36.6%-39.6%). Linkage rates were higher for full-term live birth deliveries (range 71.7%-82.2%), compared with preterm live birth deliveries (range 63.8%-72.9%).

Conclusions: Most mother-infant records were linked successfully within three commercial claims databases using only insurance subscriber ID, among those with delivery dates within three days of an infant birth date. The lower linkage rates observed in younger mothers may be due to more complex sources of health coverage in younger mothers and their infants. Most live deliveries occurred in the hospital inpatient setting and were full-term, and both groups observed high linkage rates. This linkage fosters safety surveillance on biologic products for mothers and their infants.