Cost reduction with partial step-down oral antibiotic endocarditis treatment (POET)

Background Infective endocarditis (IE) requires antibiotic therapy for up to 6 weeks and usually long hospitalization. The POET trial reported oral step-down antibiotic therapy to be non-inferior to conventional intravenous (IV) treatment only. The shift to oral antibiotic therapy allowed discharge from hospital and reduced length of stay by 16 days. The findings in the POET trial were included in the 2023 ESC guidelines for endocarditis. The purpose of this study was to estimate differences in costs in patients with IE managed with (1) conventional in-hospital IV therapy versus (2) oral step-down therapy. Methods We performed a pragmatic cost analysis informed by the cohort in the POET trial. Patients receiving oral step-down antibiotic treatment and discharged from hospital were seen twice weekly in the outpatient clinic, according to study protocol. Cost per day in-hospital was based on the regional average cost per bed day at the Department of Cardiology (€879 per day). Outpatient visits were estimated using national tariffs (for the year of the first screened patient (BG50A) (€159). In this pragmatic approach, there is a risk that healthcare costs are underestimated in both groups, why our estimates should be considered conservative. Results In total, 400 patients were randomized in POET (199 to conventional IV antibiotic therapy and 201 to oral step-down antibiotic treatment). Time to randomization was 17 days (IQR 13-24 in the IV group) and (IQR 12-24 in the oral step-down group). At randomization, both groups were clinically comparable, having reached stabilization sufficient to consider oral step-down antibiotic therapy. After randomization, median hospital length of stay was 19 days (IQR 14–25) in the IV group and 3 days (IQR 1–10) in the oral step-down group. The 199 patients randomized to conventional IV treatment had a total of 7,164 in-hospital days. The 201 patients on oral step-down treatment had 4,020 in-hospital days, corresponding to a difference of €2,763,576. With a median length of outpatient treatment of 17 days, corresponding to 4.8 outpatient visits, the patients in the oral step-down treatment group had 976 visits in the out-patient clinic, at a total cost of €155,229. Thus, the total savings in the oral group were €2,608,346, or €13,292 per patients (Figure 1). Conclusion Clinically stabilized patients with IE treated with oral step-down therapy had fewer in-hospital bed-days and the costs were reduced by €13,292 per patient. If implemented across Denmark (700 IE cases per year), this would correspond to savings of approximately 11,200 in-hospital days and €9,3 million per year.