Antibiotic consumption in the first months of life: A cross-sectional study

The factors and patterns associated with antibiotic consumption in infants are unclear. Our aim was to assess the cumulative incidence of antibiotic consumption from birth to 16 months and identify factors associated with antibiotic consumption among infants aged 4-16 months.

We conducted a cross-sectional study in 2016 in a sample of 18 882 women from Galicia, Spain, who had given birth to a live child between September 1, 2015 and August 31, 2016. We calculated the cumulative incidence of antibiotic consumption based on maternal reports regarding the infant's consumption from birth to 14 months obtained through interviews; we did not estimate consumption at ages 15 and 16 months due to the small sample size. To assess which factors were associated with antibiotic consumption, we carried out a nested case-control study matching cases and controls for birth month on a 1:1 ratio.

The cumulative incidence of antibiotic consumption among infants aged 0-14 months increased from 7.5% to 66.0%. The case-control study included data for 1852 cases and 1852 controls. Daycare attendance (OR: 3.8 [95% CI: 3.2-4.6]), having older siblings (OR: 1.8 [95% CI: 1.6-2.1]), health care visits to private clinics (OR: 1.6 [95% CI: 1.4-2.0]), and passive smoking (OR: 1.3 [95% CI: 1.1-1.6]) were associated with an increased probability of antibiotic consumption. Maternal age between 30-39 years or 40 years and over at the time of birth was associated with a decreased probability of antibiotic consumption (OR: 0.8 [95% CI, 0.7-1.0] and OR: 0.6 [95% CI: 0.5-0.8], respectively).

Some of the factors associated with antibiotic consumption in infants are modifiable and should be considered in the development of public health measures aimed at reducing antibiotic consumption.