Crude and adjusted HR and 95% CIs for the association between exposure to systemic antibiotics and ‘PcV’ in infantile age and IBD, and results from sensitivity analysis excluding those who had been diagnosed with GE 12 months prior to onset of the first IBD diagnosis
| Antibiotics | IBD | Crohn’s disease | UC | ||||||
| n | cHR (95% CI) | aHR (95% CI) | n | cHR (95% CI) | aHR (95% CI) | n | cHR (95% CI) | aHR (95% CI) | |
| Any | 25 | 1.13 (0.58 to 2.20) | 1.11 (0.57 to 2.15) | 9 | 0.72 (0.27 to 1.94) | 0.72 (0.27 to 1.92) | 11 | 1.22 (0.44 to 3.37) | 1.23 (0.45 to 3.39) |
| exl. GE | 23 | 1.28 (0.60 to 2.73) | 1.26 (0.60 to 2.64) | 7 | 0.66 (0.22 to 1.99) | 0.66 (0.23 to 1.92) | 11 | 1.39 (0.46 to 4.25) | 1.40 (0.46 to 4.25) |
| PcV | 22 | 1.27 (0.70 to 2.31) | 1.25 (0.70 to 2.26) | 8 | 0.88 (0.33 to 2.31) | 0.87 (0.33 to 2.27) | 9 | 1.19 (0.50 to 2.80) | 1.20 (0.51 to 2.81) |
| exl. GE | 21 | 1.55 (0.80 to 3.00) | 1.52 (0.80 to 2.90) | 7 | 1.07 (0.36 to 3.21) | 1.06 (0.37 to 3.10) | 9 | 1.29 (0.52 to 3.23) | 1.31 (0.53 to 3.22) |
aHR - 3 874 000 person-years; analyses adjusted for mother’s and father’s history of IBD, parental education, mother’s and father’s country of birth and mode of delivery. Those with missing information on these variables are excluded (no cases excluded).
cHR - 3 945 000 person-years.
n, cases, ie, those who have been exposed to antibiotics prior to onset of IBD/UC/CD diagnosis.
exl. GE, either bacterial or viral, according to ICD-10 codes A00-A09 12 months prior to onset of the first IBD diagnosis.
aHR, adjusted Hazard Ratio HR; cHR, crude Hazard Ratio HR; CD, Crohn’s disease; exl. GE, excluding gastroenteritis; PcV, phenoxymethylpenicillin.