Discussion

This is the first study in Asia to evaluate antimicrobial stewardship opportunities at hospital discharge. Prior studies have demonstrated the prevalence of discharge antibiotics between 20% and 30%.^{Reference Feller, Lund and Perencevich3,Reference Chavada, Davey, O’Connor and Tong4} Our study showed similar findings. In contrast, the most commonly prescribed antibiotic was amoxicillin/clavulanic acid instead of fluoroquinolones,^{Reference Yogo, Haas, Knepper, Burman, Mehler and Jenkins1,Reference Scarpato, Timko and Cluzet2} which may be due to the growing concerns of black-box warnings of fluoroquinolones and our institution’s high incidence of fluoroquinolone-resistant infections. In our study, 37.5% of the oral antibiotic prescriptions at discharge represented stewardship opportunities. Excessive antibiotic duration, especially for surgical prophylaxis, accounted for most of these opportunities. Similar findings have been reported in previous studies.^{Reference Scarpato, Timko and Cluzet2–Reference Chavada, Davey, O’Connor and Tong4}

In our study, only 61.7% of antibiotics had a documented indication. A documented indication is critical to facilitate selection of optimal antibiotic regimes and to improve communication among healthcare providers. Documentation itself also serves as a prompt to evaluate the need for an antibiotic. Given its importance, the Centers for Disease Control and Prevention (CDC) Core Elements of Hospital ASPs recommends that all antibiotics have a documented indication.⁵ Possible interventions to improve this include mandating an indication for antibiotics as part of hospital protocol or incorporating indications into the computerized prescribing order entry.

We found that antibiotics are being prescribed for a duration longer than guidelines recommend. Notably, a high proportion of these were intended for surgical prophylaxis. Studies have shown that these additional days increased risk of nephrotoxicity and Clostridium difficile infection.^{Reference Branch-Elliman, O’Brien, Strymish, Itani, Wyatt and Gupta6} Growing evidence supports a shorter duration of antibiotic treatment.^{Reference Spellberg7} We sought to develop in-house guidance on the expected duration for common infections and mandating stop dates for all antibiotics. A recent global point-prevalence survey involving our hospital showed that prolonged surgical prophylaxis was common.^{Reference Versporten, Zarb and Caniaux8} To improve this, a national work group was recently formed to investigate guideline standardization, national surveillance, and reporting.

Our study adds to the emerging literature suggesting that stewardship efforts can benefit antibiotic overuse at discharge. Pharmacists face unique challenges on making antibiotic interventions upon discharge because discharge turnaround times are often prioritized. Some of the proposed models include developing an institutional guidance for oral step-down antibiotic and duration, pharmacy-led discharge review, providing discharge advice as part of routine ASP interventions, and incorporating antibiotic time-out at discharge.^{Reference Daniels and Weber9,Reference Moehring, Dyer and Dodds Ashley10}

The limitation of our study is its small sample size in a single center, which limits its generalizability. The retrospective nature of this study may have impeded the accuracy of our assessment. We may have underestimated stewardship opportunities due to the absence of adjudication by an infectious diseases physician.

In this study, we demonstrated that the prevalence of antibiotic use upon hospital discharge was >20% and that stewardship opportunities were indicated for more than one-third of these. More novel ASP approaches should be explored to target this significant unmet need at the point of discharge, especially in the area of prolonging antibiotic therapy.