Introduction
Timely intravenous (IV) to oral antimicrobial switch (IV-oral-switch) is a well-studied antimicrobial stewardship (AMS) activity to optimise prescribing, recommended in best-practice guidelines because of its proven benefits to the patient and hospital (reduced IV line-related complications, antimicrobial costs and length of hospital stay) [1],[2]. Despite its effectiveness and safety, international studies have demonstrated that timely switch only occurs in approximately half of eligible hospitalised patients [3, 4, 5, 6].
Previous studies examining strategies to improve IV-oral-switch were typically undertaken immediately or shortly after IV-oral-switch interventions were implemented or without providing details of existing over-arching AMS programs [3, 4, 5]. It is not known whether the reported benefits reflect longer-term outcomes or whether they are applicable to settings with an existing AMS program.
Austin Health, a tertiary public hospital in Melbourne, Australia, has a long-established interdisciplinary AMS program that includes strategies to support IV-oral-switch. Included in this program are formulary restrictions requiring preauthorization for target antimicrobials (e.g. broad-spectrum agents) that limits empiric therapy to two or three days after which a new authorisation is required. Such a system encourages early re-assessment and consideration of key AMS interventions (IV-oral-switch, de-escalation or discontinuation of therapy). The preauthorization system is a combination of phone approval via an Infectious Diseases (ID) physician and computerised approval [7], with daily oversight from ID pharmacists. Since November 2017, the AMS program also included a local IV-oral-switch guideline and pocket-sized summary cards for clinicians outlining criteria for IV-oral-switch and recommendations for oral alternatives (Supplement).
The aim of this study was to explore concordance with IV-oral-switch guidelines in the context of a long-standing, tightly regulated AMS program.