Table 1.
Demographic and Clinical Characteristics of Children in the Study Cohort and their Mothers, according to Antibiotic Exposure in the First 2 Years of Life.
| Not exposed (n = 4352) | Exposed (n = 10220) | All (n = 14572) | |
|---|---|---|---|
| Children | |||
|
Sex – no. (%) Female Male |
2223 (51.1) 2129 (48.9) |
4803 (47.0) 5417 (53.0) |
7026 (48.2) 7546 (51.8) |
| Duration of follow-up – years a | |||
| Median (IQR) | 8.4 (6.1–10.4) | 9.1 (6.5–11.7) | 8.8 (6.4–11.4) |
| Birth weight - kg | |||
| Median (IQR) | 3.4 (3.1–3.7) | 3.4 (3.1–3.8) | 3.4 (3.1–3.8) |
| Ethnicity – no. (%) | |||
| White | 2951 (67.8) | 7397 (72.4) | 10348 (71.0) |
| Black | 365 (8.4) | 934 (9.1) | 1299 (8.9) |
| Asian | 338 (7.8) | 617 (6.0) | 955 (6.6) |
| Hawaiian/Pacific Islander | 19 (0.4) | 33 (0.3) | 52 (0.4) |
| American Indian | 18 (0.4) | 28 (0.3) | 46 (0.3) |
| Other/unknown | 661 (15.2) | 1211 (11.8) | 1872 (12.8) |
| Cesarean section – no. (%) | 940 (21.6) | 2434 (23.8) | 3374 (23.2) |
| Number of prescriptions – no. (%) | |||
| 1–2 | - | 4560 (44.6) | |
| 3–4 | - | 2434 (23.8) | |
| 5+ | - | 3226 (31.6) | |
| Categories – no. (%) | |||
| Penicillins | - | 9306 (63.9) | |
| Cephalosporins | - | 3401 (23.3) | |
| Sulfonamides | - | 777 (5.3) | |
| Macrolides | - | 3724 (25.6) | |
| Mothers | |||
| Age - years | |||
| Median (IQR) | 28.7 (24.7–32.5) | 29.1 (25.5–32.6) | 29.0 (25.3–32.6) |
| Education – no. (%) | |||
| High school or less | 789 (21.4) | 1614 (17.7) | 2403 (18.8) |
| Some college/4years | 1921 (52.1) | 4716 (51.8) | 6637 (51.9) |
| Post graduate | 978 (26.5) | 2766 (30.4) | 3744 (29.3) |
| Smoking – no. (%) | 457 (10.5) | 1151 (11.3) | 1608 (11.0) |
| Antibiotics during pregnancy – no. (%) | 1538 (35.3) | 4094 (40.1) | 5632 (38.7) |
a
Duration of follow-up includes also the first 2 years of life. IQR denotes interquartile range.