TABLE 2

Multivariable Linear Regression Results for the Association of Any Exposure to Antibiotics at <24 Months of Age With the BMI z Score at 48–<72 Months of Age, by Timing of Antibiotic Prescription

AntibioticsNo Complex Chronic Condition, N = 310 947Complex Chronic Condition, N = 51 603
Model 1,a β (95% CI)Model 2,b β (95% CI)Model 1,a β (95% CI)Model 2,b β (95% CI)
Any, mo
 0–<24.08 (0.07 to 0.08).04 (0.03 to 0.05).09 (0.07 to 0.11).06 (0.04 to 0.09)
 0–<6c,d.10 (0.09 to 0.11).05 (0.04 to 0.06).09 (0.06 to 0.12).05 (0.02 to 0.08)
 6–<12c,d.07 (0.07 to 0.08).03 (0.02 to 0.04).08 (0.05 to 0.10).04 (0.01 to 0.06)
 12–<24c,d.06 (0.06 to 0.07).02 (0.01 to 0.03).09 (0.07 to 0.12).06 (0.03 to 0.08)
Broad spectrum, mo
 0–<24.08 (0.07 to 0.09).04 (0.03 to 0.05).09 (0.07 to 0.12).07 (0.05 to 0.10)
 0–<6c,d.09 (0.07 to 0.11).04 (0.02 to 0.06).09 (0.05 to 0.12).05 (0.01 to 0.09)
 6–<12 moc,d.08 (0.07 to 0.09).03 (0.02 to 0.05).08 (0.05 to 0.11).05 (0.01 to 0.08)
 12–<24c,d.07 (0.06 to 0.08).03 (0.02 to 0.04).10 (0.08 to 0.13).07 (0.04 to 0.10)
Narrow spectrum,e mo
 0–<24.05 (0.04 to 0.06).02 (0.01 to 0.03).05 (0.02 to 0.08).03 (−0.01 to 0.06)
 0–<6c,d.10 (0.08 to 0.11).05 (0.04 to 0.07).09 (0.04 to 0.13).04 (−0.01 to 0.08)
 6–<12c,d.06 (0.05 to 0.07).02 (0.01 to 0.04).05 (0.01 to 0.09).01 (−0.03 to 0.05)
 12–<24c,d.04 (0.03 to 0.05).01 (0.00 to 0.02).05 (0.01 to 0.08).02 (−0.02 to 0.06)
  • a Corrected for clustering by site.

  • b Corrected for clustering by site and adjusted for sex, race, ethnicity, preterm birth, asthma, corticosteroid episodes (continuous, 0–4+) at 0–<24 months of age, number of encounters (continuous, log transformed) at 0–<24 months of age, infection episodes (continuous, log transformed) at 0–<24 months of age, and age at outcome.

  • c For exposure time windows, Model 2 was additionally adjusted for previous antibiotics: (1) antibiotics at 6–<12 months, adjusted for 0–<6 months antibiotics and (2) antibiotics at 12–<24 months, adjusted for 0–<12 months antibiotics.

  • d For exposure time windows, covariates were used during the same time window (corticosteroids and encounters): (1) antibiotics at 0–<6 months, covariates used for 0–<6 months; (2) antibiotics at 6–<12 months, covariates used for 6–<12 months; and (3) antibiotics at 12–<24 months, covariates used for 12–<24 months.