Introduction Antibiotic use drives antibiotic resistance. The UK antimicrobial resistance (AMR) strategy aims to reduce antibiotic use. We aimed to quantify excess antibiotic use in a district general hospital in south-west England.

Methods Medical patients discharged in August 2020 who had received antibiotics were included. An audit tool of antibiotic prescribing appropriateness was used to collect relevant clinical information regarding each patient case. The appropriateness of antibiotic use was then determined by two infection specialists and excess days of therapy (DOTs) calculated.

Results 647 patients were discharged in August 2020. Of the 1658 antibiotic DOTs for the 184 patients reviewed, 403 (24%) were excess DOTs. The excess antibiotic DOTs were prescribed in 92 patients (50%); 112/403 (27.8%) excess DOTs originated at the initiation of antibiotic therapy (time point A); 184/403 (45.7%) of excess DOTs occurred at the antibiotic review pre-72 hours (time point B); and 107/403 (26.6%) of excess DOTs were due to protracted antibiotic courses (time point C).

Conclusion 24% of antibiotic DOTs were deemed unnecessary. The greatest opportunity to reduce antibiotic use safely was the pre-72 hours antibiotic review, which may provide a target for reducing excess antimicrobial therapy in line with the national AMR strategy.