[Impact of an infectious diseases consultation service on the quality of care and the survival of patients with infectious diseases]

While trained infectious diseases (ID) specialists are regularly involved in inpatient and outpatient care in the United States and Canada, these specialized services are only rarely established in Germany. This article aims to summarize the findings of numerous studies that investigated the impact of ID consultation services on patient care and outcome in patients suffering from infectious diseases. The strongest evidence for a clinical benefit is found in the context of Staphylococcus aureus bacteremia (SAB), where in-hospital- and day-30 mortality was significantly and consistently reduced by about 40% in patients that were evaluated and treated in cooperation with an ID physician. Furthermore, studies revealed that this effect was associated with an improved adherence to standards of care. Newer studies show a reduced length of hospital stay due to ID consultations, especially if patients are evaluated early in the course of their hospital stay. Of note, informal or curbside consultations do not seem to be equivalent to a formal ID consultation with bedside patient evaluation. Studies in other patient groups (solid organ transplant recipients or intensive care unit patients) or in the context of other infections (infective endocarditis, pneumonia, other bloodstream infections) also revealed positive effects of ID consultations. Higher rates of appropriate empirical and targeted antimicrobial treatments and de-escalation strategies due to successful pathogen identification were documented. These modifications resulted in lower treatment costs and decreased antimicrobial resistance development. Although there are methodological limitations in single studies, we consider the consistent and reproducible positive effects of ID consultations shown in studies in different countries and health care systems as convincing evidence for the improved quality of care and treatment outcomes in patients with infectious diseases. Thus, strong consideration should be given to establish ID consultation services in small and medium sized hospitals as well.