Paediatric outpatient antibiotic utilization patterns and use of healthcare services before, during and after the COVID-19 pandemic: interrupted time series analysis using data from Norway and Japan

OBJECTIVES: Quantification of prescription of antimicrobial agents and use of paediatric outpatient services before, during and after the COVID-19 pandemic. METHODS: We conducted a population-based study using Norwegian linked health registries and Japanese claims (2018-2023). Paediatric antibiotic prescription rates, broad-spectrum use, and proportion of antibiotic prescriptions with prior presumed bacterial infection diagnoses were analysed monthly, overall and by age groups and sex. Interrupted time series analyses were performed to evaluate pandemic-related changes, expressed in rate ratio (RR) and its CI, using March 2020 as the interruption point and the pre-pandemic trend/level as reference. RESULTS: Data on 5.5 million children and 19.5 million antibiotic prescriptions were analysed. Before the pandemic, antibiotic prescribing was higher in Japan (120-200/1000 children/month) than in Norway (10-20/1000). At pandemic onset, rates fell by 45% in Norway (RR = 0.55; 95% CI, 0.45-0.67) and by 53% in Japan (RR = 0.47; 95% CI, 0.41-0.55), then by 2023 had returned to expected levels. Broad-spectrum antibiotic use was much higher in Japan (70%) compared with Norway (10%) before the pandemic. However, Norway experienced a sharp 20% increase whereas Japan remained largely unchanged post-pandemic. The proportion of prescriptions with a prior presumed bacterial diagnosis was between 50% and 65% before the pandemic then decreased modestly by 5%-10% at pandemic onset, followed by gradual rebound in both countries. CONCLUSIONS: The COVID-19 pandemic significantly altered paediatric antibiotic prescribing in both countries. Sustained antibiotic stewardship efforts are needed to ensure appropriate paediatric antibiotic use in the post-pandemic era.