An interdisciplinary infectious disease support team with longitudinal process interventions is associated with lower 28-day mortality in bacteremia: a single-center cohort study

Abstract Objective: We aimed to evaluate the impact of transitioning from a conventional antimicrobial stewardship team (AST) to an interdisciplinary infectious disease support team (IDST) on patient mortality. Design: Single-center retrospective cohort study. Setting: Yamanashi Prefectural Central Hospital. Patients: We included patients with bacteremia during the AST and IDST periods. Methods: We implemented an interdisciplinary IDST that provided comprehensive support beyond antimicrobial selection and treatment. We compared 28-day mortality outcomes in hospitalized patients with bacteremia during the AST-only period (April 2021–March 2022) and the IDST-intervention period (April 2022–March 2023). Cox proportional hazards modeling was used to assess 28-day mortality; multivariable logistic regression served as a prespecified sensitivity analysis. Between-group differences were tested using two-sided tests ( P < .05), and 95% confidence intervals (CIs) were reported. Results: Among the 854 patients (413 in the AST group and 441 in the IDST group), AST interventions did not significantly decrease 28-day mortality compared with no-intervention cases (20.8% vs 23.3%, P = .630). However, intervention by the IDST significantly reduced 28-day mortality compared with the no-IDST group (16.1% vs 25.2%, P = .019). In the multivariate Cox proportional hazards model, IDST interventions remained independently associated with a reduced 28-day mortality (hazard ratio, 0.518; 95% CI, 0.325–0.826; P = .006). Conclusions: Transitioning from an AST to an interdisciplinary IDST model was associated with lower 28-day mortality in bacteremia cases, possibly due to sustained diagnostic and therapeutic interventions. Our findings support stewardship as a team-based process and may significantly impact patient outcomes by maintaining involvement until treatment completion and clinical stabilization.