Antimicrobial exposure during infancy in a longitudinal California cohort

Area of Science:

• Pediatrics
• Infectious Diseases
• Public Health

Background:

• Antimicrobial exposure patterns in infants are not well-described in US populations.
• Understanding these patterns is crucial for public health and clinical practice.

Purpose of the Study:

• To describe temporal and sociodemographic patterns of antimicrobial exposure in the first year of life.
• To identify predictors of antimicrobial exposure in early versus late infancy.

Main Methods:

• Longitudinal analysis of 345,550 infants born 1998-2014 in a large US integrated health system.
• Utilized comprehensive electronic health records for inpatient and outpatient antimicrobial dispensings.
• Summarized exposure by maternal/infant characteristics, birth year, inpatient/outpatient status, age, and drug class.

Main Results:

• 44% of infants received at least one antimicrobial dose.
• Antimicrobial exposure decreased over time, primarily due to reduced late-infancy outpatient dispensings (penicillins).
• Early infancy (0-3 months) exposure strongly predicted by birth characteristics (NICU, gestational age); late infancy (3-12 months) exposure modestly predicted by sociodemographics.

Conclusions:

• Predictors of antimicrobial exposure differ between early and late infancy.
• Early infancy exposures are strongly correlated with birth characteristics.
• Decreased cumulative infant antimicrobial exposure is linked to reduced late-infancy outpatient dispensings.