Impact of a clinical pharmacist-led stewardship programme on antibiotic utilisation and clinical outcomes in thoracic surgery: a retrospective interrupted time-series study at a tertiary hospital in China

OBJECTIVES: This study aims to assess the impact of clinical pharmacist-led antimicrobial stewardship on antibiotic use and postoperative pulmonary infection in a surgical department. DESIGN: Retrospective and cross-sectional. SETTING: A tertiary hospital in Wuhan, China. PARTICIPANTS: A total of 9157 patients who underwent video-assisted thoracoscopic lung surgery (VATLS) were included (4949 and 4208 pre-implementation and post-implementation). METHODS: test, Fisher's exact test, t-test or Mann-Whitney U test, as appropriate. OUTCOME MEASURES: Antibiotic use intensity (defined daily dose/100 bed-days), antibiotic spectrum coverage (scores/100 bed-days), postoperative pulmonary infection rates, the proportion and the duration of antibiotic use. RESULTS: Following implementation, antibiotic use intensity decreased immediately by 96.65 defined daily doses/100 bed-days (95% CI -122.56 to -70.74; p<0.001). Antibiotic spectrum coverage (ASC) also showed an immediate reduction of 4.77 scores/100 bed-days (95% CI -6.12 to -3.42; p<0.001), although a gradual upward trend in ASC was observed during the post-implementation period. No significant change was seen for postoperative pulmonary infection rates between the two periods. Prescribing patterns shifted towards narrower-spectrum agents: the proportion of first-generation cephalosporins increased from 17.6% to 45.5% (p<0.001), while usage of fourth-generation cephalosporins (12.3% to 1.5%), β-lactam/β-lactamase inhibitors (63.9% to 12.6%), quinolones (57.4% to 27.4%), carbapenems (0.8% to 0.4%) and glycopeptides (8.2% to 3.1%) declined significantly (all p<0.05). The median duration of antimicrobial therapy was shortened across most antibiotic classes. CONCLUSION: Clinical pharmacist-led antimicrobial stewardship can reduce the antibiotic use intensity among patients undergoing VATLS in thoracic surgery, decrease the use of broad-spectrum antibiotics and shorten the duration of antibiotic therapy.