Evaluation of duration of antibiotic therapy across hospitals in Scotland including the impact of COVID-19 pandemic: a segmented interrupted time series analysis

Little is known about the duration of antibiotic use in hospital settings. We evaluated the duration of hospital antibiotic therapy for four commonly prescribed antibiotics (amoxicillin, co-amoxiclav, doxycycline, and flucloxacillin) including the assessment of COVID-19 impact. A repeated, cross-sectional study using the Hospital Electronic Prescribing and Medicines Administration system (January/2019-March/2022). Monthly median duration of therapy/duration categories was calculated, stratified by routes of administration, age, and sex. The impact of COVID-19 was assessed using segmented time-series analysis. There were significant variations in the median duration of therapy across routes of administration (P < 0.05), with the highest value among those antibiotic courses composed of both oral and IV antibiotics (‘Both’ group). Significantly higher proportions of prescriptions within the ‘Both’ group had a duration of >7 days compared to oral or IV. The duration of therapy differed significantly by age. Some small statistically significant changes in the level/trends of duration of therapy were observed in the post-COVID-19 period. No evidence for prolonged duration of therapy were observed, even during COVID-19 pandemic. The duration of IV therapy was relatively short, suggesting timely clinical review and consideration of IV to oral switch. Longer duration of therapy was observed among older patients.