Leveraging inpatient antimicrobial stewardship infrastructure to improve antimicrobial-prescribing at hospital discharge

Background: Antimicrobial overuse is one of the strongest risk factors for the emergence of antimicrobial resistance, an urgent public health problem. Antimicrobial stewardship programs (ASPs) are hospital-based programs that can reduce unnecessary inpatient antimicrobial use and are therefore an essential tool for

addressing the crisis of antimicrobial resistance. ASPs are mandated in VHA. Significance: VHA hospitals are only required to monitor their inpatient antimicrobial use. However, at least 40% of antimicrobial exposure associated with a VHA hospital stay is prescribed at hospital discharge and is taken by the patient after discharge (i.e. post-discharge). These post-discharge antimicrobial prescriptions are

frequently unnecessary or sub-optimal. Reducing post-discharge antimicrobial overuse will minimize patient harm, such as Clostridioides difficile infections, antimicrobial resistance, and adverse drug events. Innovation and Impact: This proposal will address two critical gaps in the literature. First, standard ASP

metrics do not capture post-discharge antimicrobial use and therefore miss a substantial amount of hospital- related antimicrobial exposure. This proposal will evaluate factors that contribute to variation in post-discharge antimicrobial use across patients and hospitals in order to inform both metric development and the design of

future stewardship interventions. Second, while there are evidence-based strategies for safely reducing inpatient antimicrobial use, it is unclear how current inpatient ASP activities can decrease post-discharge antimicrobial overuse. This proposal will explore how inpatient ASP infrastructure, which all VHA hospitals are

expected to have, can be leveraged to reduce unnecessary post-discharge antimicrobial-prescribing. Specific Aims: Aim 1: Identify factors that contribute to variation in post-discharge antimicrobial use in VHA acute-care admissions across all facilities by evaluating potential patient-level, hospital-level, and

environmental effects. Identify hospitals that have low observed-to-expected post-discharge antimicrobial use, low risk-adjusted inpatient antimicrobial use, and perform well on clinical outcomes in antimicrobial-treated patients. Aim 2: Determine whether being admitted to a hospital with a discharge-focused stewardship process

is associated with less post-discharge antimicrobial exposure, after adjusting for differences in case-mix, ID expertise, inpatient antimicrobial exposure, and the intensity of inpatient ASP activities. Aim 3: Using qualitative methods, evaluate attitudes and processes that impede or foster reductions in unnecessary post-discharge

antimicrobial use. We will perform site visits at 6 high- and 4 low-performing sites, as identified in Aim 1. Methodology: Aim 1 will use VINCI data and linear mixed models to identify factors that influence post- discharge antimicrobial use. Aim 1 will also rank hospitals on their performance on inpatient and post-

discharge antimicrobial use plus associated clinical outcomes. In Aim 2, we will leverage VINCI data and findings from a mandatory hospital-level stewardship survey conducted in VHA during November 2020. We will evaluate the effect of a discharge-specific stewardship process on post-discharge antimicrobial use. In Aim 3,

we will conduct semi-structured interviews with key stakeholders at 10 hospitals to explore determinants of post-discharge antimicrobial overuse and perceptions of the post-discharge antimicrobial use metric that we developed in Aim 1. Our approach will be based in the i-PARIHS framework. Next Steps/Implementation: The standardized hospital-level metrics we develop in Aim 1 could be

incorporated into an interactive ASP dashboard our Patient Safety Center of Inquiry has already built and is pilot-testing in VISN 23. Our findings from Aims 2 and 3 could be incorporated into future stewardship surveys within VHA while informing the processes local ASPs choose to implement to reduce post-discharge

antimicrobial overuse. Our findings could serve as the basis for a multicenter, audit-and-feedback trial focused on stewardship at hospital discharge and future work around re-designing ASP processes at discharge.