Clostridioides difficile infection and antibiotic prescribing at a regional hospital in Australia: a case-control study.

Background: Clostridioides difficile infections (CDI) increased at a large, regional hospital in New South Wales, Australia, in 2021, coinciding with an increase at hospitals Australia wide. We aimed to investigate the association between antibiotic prescribing practices and hospital-acquired CDI at the hospital to inform antimicrobial stewardship (AMS) programs.

Methods: We conducted a retrospective case-control study for the period July 1, 2018, and June 30, 2022. Seventy hospital-acquired CDI cases were selected for the study. Cases were matched on a 1:2 basis with randomly selected controls based on date of hospitalization and age group. We conducted a multivariable analysis to explore possible risk factors for infection. We compared cases and controls who were administered antibiotics to determine if rates of inappropriate antibiotic prescriptions differed between cases and controls.

Results: The multivariable model found that use of cephalosporins (third, fourth, or fifth generation) (adjusted odds ratio (aOR) 3.82, 95% confidence interval (CI) 1.35-10.84), use of penicillins (broad or extended broad spectrum) (aOR 5.79, 95% CI 2.15-15.58), and increased complexity of comorbidities (aOR 1.22, 95% CI 1.02-1.45) were independently associated with CDI. In patients who had antibiotics administered during their admission, inappropriate antibiotic prescribing (OR 5.68, 95% CI 1.95-16.48) and non-compliance with antibiotic prescribing guidelines (OR 5.01, 95% CI 1.07-14.76) were associated with CDI.

Conclusions: Our study showed that antibiotic prescribing practices were associated with hospital-acquired CDI at the hospital during the study period. The results reinforce the importance of compliance with antibiotic guidelines and provide further evidence for AMS programs to reduce CDI.