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.