Hospital antimicrobial stewardship funding and resourcing impact on broad-spectrum antibiotic use: a cross-sectional study

Background: Antimicrobial stewardship programs (ASPs) aim to mitigate antimicrobial resistance (AMR) by optimizing antibiotic use including reducing unnecessary broad-spectrum therapy. This study evaluates the impact of ASP funding and resources on the use of broad-spectrum antibiotics in Ontario hospitals. Methods: We conducted a cross-sectional study of antimicrobial use (AMU) across 63 Ontario hospitals from April 2020 to March 2023. The Ontario ASP Landscape Survey provided data on ASP resourcing and antibiotic utilization. The main outcome was the proportion of all antibiotics that were broad-spectrum, defined as: fluoroquinolones; third-generation cephalosporins; beta-lactam/beta-lactamase inhibitors; carbapenems; clindamycin; and parenteral vancomycin. Secondary outcomes included the proportions of individual antibiotic classes listed above and anti-pseudomonal agents. Statistical analysis involved logistic regression to determine the odds ratio (OR) of the association between ASP funding/resourcing and broad-spectrum antibiotic use. Results: Among 63 hospitals, 48 reported designated ASP funding/resources. Median broad-spectrum antibiotic use was 52.5%. ASP funding/resources was not associated with overall broad-spectrum antibiotic use (0.97, 95% CI: 0.75-1.25, P = 0.79). However, funding was associated with lower use of fluoroquinolones (OR 0.67, 95% CI: 0.46-0.96, P = 0.03), clindamycin (OR 0.69, 95% CI: 0.47-1.00, P = 0.05), and anti-pseudomonal agents (OR 0.76, 95% CI: 0.59-0.98, P = 0.03). Conclusion: The presence of designated funding and resources for hospital ASPs is linked to reduced use of specific broad-spectrum antibiotics but not overall broad-spectrum antibiotic use. Enhancing ASP resourcing may be an important factor in limiting targeted antibiotic use, thereby increasing the effectiveness of efforts to mitigate AMR.