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

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.