Antimicrobial exposure during infancy in a longitudinal California cohort

Hannah C Barca; Jeannette Ferber; Megan Richards; Matthew Strickland; Alfred J Fernandez; De-Kun Li; Lyndsey A Darrow

doi:10.1038/s41390-024-03171-x

Antimicrobial exposure during infancy in a longitudinal California cohort

Pediatr Res. 2024 Apr 3. doi: 10.1038/s41390-024-03171-x. Online ahead of print.

Authors

Hannah C Barca¹, Jeannette Ferber², Megan Richards³, Matthew Strickland³, Alfred J Fernandez⁴, De-Kun Li², Lyndsey A Darrow³

Affiliations

¹ School of Public Health, University of Nevada, Reno, Reno, NV, USA. hannahcbarca@gmail.com.
² Kaiser Permanente Division of Research, Oakland, CA, USA.
³ School of Public Health, University of Nevada, Reno, Reno, NV, USA.
⁴ Children's Healthcare of Atlanta, Atlanta, GA, USA.

PMID: 38570559
DOI: 10.1038/s41390-024-03171-x

Abstract

Background: To describe temporal and sociodemographic patterns of antimicrobial exposure during the first year of life in a large US cohort.

Methods: Singleton infants born 1998-2014 enrolled in Kaiser Permanente Northern California integrated health system (n = 345,550) were followed longitudinally via comprehensive electronic health records, capturing all systemic antimicrobial inpatient administrations and outpatient dispensings. Antimicrobial exposure was summarized by maternal and infant characteristics, birth year, inpatient/outpatient status, age in months, and drug class.

Results: Overall, 44% of infants in this cohort received at least one dose of antimicrobials during infancy. Decreases over time were driven by reduced outpatient dispensings specifically in later infancy, primarily for penicillins. Among infants receiving any antimicrobials the median number of exposure-days was 16. Inpatient dispensings peaked in the first 30 days of life and outpatient dispensings peaked at 10-11 months. Birth characteristics (i.e., NICU admission, gestational age) were strong independent predictors of antimicrobial exposure between 0- < 3 months; sociodemographic factors were modest predictors of exposure for 3-12 months.

Conclusion: Predictors of antimicrobial exposure in early and late infancy are distinct with early infancy exposures highly correlated to birth characteristics. The cumulative proportion of infants exposed has decreased due to fewer late infancy outpatient dispensings.

Impact: Comprehensive antimicrobial exposure histories and the maternal and infant characteristics predicting exposure have not been well described in US populations. This analysis provides estimates of cumulative antimicrobial exposures by sociodemographic factors, delivery characteristics, month of life, inpatient/outpatient status, and antibiotic class among one of the largest US HMOs. Predictors of early infancy antimicrobial exposures differ from those in late infancy, with early exposures strongly correlated to birth characteristics and late infancy exposures modestly related to sociodemographic factors. Antimicrobial exposure among infants decreased over the time period primarily due to reduced outpatient dispensings in later infancy.