Antibiotic use in children before, during and after hospitalisation

Purpose To investigate ambulatory antibiotic use in children during 1 year before and 1 year after in-hospital antibiotic exposure compared to children from the general population that had not received antibiotics in-hospital. Methods Explorative data-linkage cohort study from Norway of children aged 3 months to 17 years. One group had received antibiotics in-Hospital (H+), and one group had not received antibiotics in-hospital (H-). The H+ group was recruited during admission in 2017. Using the Norwegian Population Registry, 10 children from the H- group were matched with one child from the H+ group according to county of residence, age and sex. We used the Norwegian Prescription Database to register antibiotic use 1 year before and 1 year after the month of hospitalisation. Results Of 187 children in the H+ group, 83 (44%) received antibiotics before hospitalisation compared to 288/1870 (15%) in the H- group, relative risk (RR) 2.88 (95% confidence interval 2.38-3.49). After hospitalisation, 86 (46%) received antibiotics in the H+ group compared to 311 (17%) in the H- group, RR 2.77 (2.30-3.33). Comorbidity-adjusted RR was 2.30 (1.84-2.86) before and 2.25 (1.81-2.79) after hospitalisation. RR after hospitalisation was 2.55 (1.99-3.26) in children 3 months-2 years, 4.03 (2.84-5.71) in children 3-12 years and 2.07 (1.33-3.20) in children 13-17 years. Conclusions Children exposed to antibiotics in-hospital had two to three times higher risk of receiving antibiotics in ambulatory care both before and after hospitalisation. The link between in-hospital and ambulatory antibiotic exposure should be emphasised in future antibiotic stewardship programs.