Impact of a Diagnosis-Centered Antibiotic Stewardship on Incident Clostridioides difficile Infections in Older Inpatients: An Observational Study

In 2015, a major increase in incident hospital-onset Clostridioides difficile infections (HO-CDI) in a geriatric university hospital led to the implementation of a diagnosis-centered antibiotic stewardship program (ASP). We aimed to evaluate the impact of the ASP on antibiotic consumption and on HO-CDI incidence. The intervention was the arrival of a full-time infectiologist in the acute geriatric unit in May 2015, followed by the implementation of new diagnostic procedures for infections associated with an antibiotic withdrawal policy. Between 2015 and 2018, the ASP was associated with a major reduction in diagnoses for inpatients (23% to 13% for pneumonia, 24% to 13% for urinary tract infection), while median hospital stays and mortality rates remained stable. The reduction in diagnosed bacterial infections was associated with a 45% decrease in antibiotic consumption in the acute geriatric unit. HO-CDI incidence also decreased dramatically from 1.4 parts per thousand bed-days to 0.8 parts per thousand bed-days in the geriatric rehabilitation unit. The ASP focused on reducing the overdiagnosis of bacterial infections in the acute geriatric unit was successfully associated with both a reduction in antibiotic use and a clear reduction in the incidence of HO-CDI in the geriatric rehabilitation unit.