Outpatient Parenteral Antibiotic Therapy for Diabetic Foot Osteomyelitis in an Uninsured and Underinsured Cohort

Background: Diabetic foot osteomyelitis (DFO) is usually treated with prolonged outpatient parenteral antibiotic therapy (OPAT). Evaluation and treatment of nonantibiotic aspects of DFO (eg, peripheral artery disease) are also recommended. There are limited data regarding OPAT practice patterns and outcomes for DFO. Methods: Single-center observational study of patients receiving OPAT for DFO in a large United States public hospital between January 2017 and July 2019. We abstracted data regarding microbiology test, antibiotics, clinical outcomes, and nonantibiotic DFO management. Results: Ninety-six patients were included and some had >1 DFO-OPAT course during the study period (106 DFO-OPAT courses included). No culture was obtained in 40 (38%) of courses. Methicillin-resistant Staphylococcus aureuswas cultured in 15 (14%) and Pseudomonas aeruginosa in 1 (1%) of DFO-OPAT courses. An antibiotic with methicillin-resistant S. aureus activity (vancomycin or daptomycin) was used in 79 (75%) of courses, and a parenteral antibiotic with antipseudomonal activity was used in 7 (6%) of courses. Acute kidney injury occurred in 19 (18%) DFO-OPAT courses. An ankle-brachial index measurement was obtained during or 6 months before the first DFO-OPAT course for 44 (49%) of patients. Forty-two patients (44%) died or had an amputation within 12 months of their initial hospital discharge. Conclusions: We found high rates of empiric antibiotic therapy for DFO and low uptake of the nonantibiotic aspects of DFO care. Better implementation of microbiological tests for DFO in addition to stronger integration of infectious disease and noninfectious diseases care could improve DFO outcomes.