Clinical impact of accepting or rejecting a recommendation from a clinical decision support system-assisted antibiotic stewardship program.

Background: Outcomes associated with physician responses to recommendations from an antimicrobial stewardship program (ASP) at an individual patient level have not yet been assessed. We aimed to compare clinical characteristics and mortality risk among patients for whom recommendations from an ASP were accepted or refused.

Methods: A prospective cohort study was performed with hospitalized adults who received intravenous or oral antimicrobials at a 677-bed academic centre in Canada in 2014-2017. We included patients with an alert produced by a clinical decision support system (CDSS) for whom a recommendation was made by the pharmacist to the attending physician. The outcome was 90-day in-hospital all-cause mortality.

Results: We identified 3,197 recommendations throughout the study period, of which 2,885 (90.2%) were accepted. The median length of antimicrobial treatment was significantly shorter when a recommendation was accepted (0.26 versus 1.78 d; 0.001). Refusal of a recommendation was not associated with mortality (odds ratio 1.32; 95% confidence interval, 0.93 to 1.89; 0.12). The independent risk factors associated with in-hospital mortality were age, Charlson Comorbidity Index score, admission to a critical care unit, duration between admission and recommendation, and issuance of a recommendation on a carbapenem.

Conclusions: The duration of antimicrobial treatment was significantly shorter when a recommendation originating from a CDSS-assisted ASP program was accepted. Future prospective studies including potential residual confounding variables, such as the source of infection or physiological derangement, might help in understanding whether CDSS-assisted ASP will have a direct impact on patient mortality.