Table 7.
Hazard ratios (HR) and 95% confidence intervals for asthma in relation to age at exposure to airway and urinary tract/skin antibiotics in childhood for children with siblings
| Age (years) | Airway antibiotics | Urinary tract/skin antibiotics | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Crude | Adjusted* | Crude | Adjusted* | ||||||||
| Cases† | HR (95% CI) | Cases† | HR (95% CI) | Cases† | HR (95% CI) | Cases† | HR (95% CI) | ||||
| 0-0.5 | 1075 | 2.16 (1.68 to 2.79) | 961 | 2.36 (1.78 to 3.13) | 129 | 0.70 (0.41 to 1.20) | 114 | 0.85 (0.47 to 1.55) | |||
| 0.5-1 | 1655 | 1.56 (1.37 to 1.77) | 1494 | 1.51 (1.31 to 1.73) | 255 | 0.93 (0.71 to 1.21) | 226 | 0.94 (0.70 to 1.25) | |||
| 1-1.5 | 931 | 1.85 (1.59 to 2.14) | 837 | 1.91 (1.62 to 2.24) | 234 | 0.98 (0.73 to 1.30) | 216 | 0.98 (0.72 to 1.33) | |||
| 1.5-2 | 546 | 1.50 (1.21 to 1.86) | 496 | 1.54 (1.22 to 1.95) | 175 | 1.02 (0.71 to 1.45) | 161 | 0.98 (0.66 to 1.44) | |||
| ≥2 | 628 | 1.38 (1.04 to 1.84) | 580 | 1.38 (1.02 to 1.86) | 292 | 0.97 (0.67 to 1.41) | 264 | 0.95 (0.63 to 1.42) | |||
*Adjusted for sex, birth weight, gestational age, mode of delivery, respiratory diagnoses as newborn, maternal age at delivery, parity, family situation, maternal exposure to antibiotics in fetal life, age as analysis time scale, and parity included as interaction term with age. Individuals with missing information on included variables excluded.
†All families discordant on asthma are included in analyses, but only those also discordant on exposure contribute to estimates in table, therefore number of cases is number of families with siblings discordant for both antibiotic exposure and asthma.