Discharge Delays and Costs Associated With Outpatient Parenteral Antimicrobial Therapy for Multidrug-Resistant Organisms: A Retrospective Cohort Study

Background Outpatient parenteral antimicrobial therapy (OPAT) coordination is challenging in multidrug-resistant organism (MDRO)–infected patients. The study purpose was to describe barriers and medication costs associated with OPAT utilizing therapies for MDRO. Methods This was an institutional review board–approved, retrospective cohort of hospitalized, MDRO-infected adults medically stable for discharge (MSDC) with an intended OPAT for cefiderocol, ceftazidime/avibactam, ceftolozane/tazobactam, eravacycline, meropenem/vaborbactam, or tigecycline from 1 January 2017 through 31 March 2025. Cohorts included patients who received an intended or modified OPAT regimen, defined as transition to alternative intravenous (IV)/oral therapy, in-hospital completion of IV therapy, or in-hospital death. Secondary outcomes included post-MSDC medication costs, length of stay (LOS), and oral-switch therapy opportunities. Results One hundred-twenty patients were included; 29% received a modified OPAT regimen. β-lactams were the most intended OPAT regimen (67%). Patients with a modified OPAT regimen had higher median (interquartile range [IQR]) medication costs ($4828 [$1209–$18 066] vs $1975 [$494–$4872], P < .001), more frequently experienced discharge delays ≥1 day (89% vs 66%, P = .011) and discharge referral disposition changes (40% vs 16%, P = .006), and had a prolonged median (IQR) LOS (20 [14–46] vs 13 [7–27] days, P = .023), compared to those who received an intended OPAT regimen. Oral-switch therapy opportunities were identified in 40% of patients. After adjusting for Medicaid, referral disposition changes (adjusted odds ratio [aOR], 3.46 [95% confidence interval {CI}, 1.21–9.89) and initial β-lactam therapy (aOR, 4.08 [95% CI, 1.55–10.79]) were associated with an increased odds of receiving a modified OPAT regimen. Conclusions Modified OPAT regimens are common and associated with increased costs, prolonged LOS, and discharge delays in MDRO-infected patients. These findings support the use of oral-switch therapy and improved care coordination.