Empirical Antibiotic Therapy in Diabetic Foot Ulcer Infection Increases Hospitalization.

Background: We evaluated the outcomes associated with initial antibiotic management strategies for infected diabetic foot ulcers (DFUs) diagnosed in an outpatient multidisciplinary center. Methods: Consecutive outpatient individuals with infected DFUs, stratified according to Infectious Diseases Society of America infection severity, were followed for 1 year from the initial antibiotic administration to treat acute infection. The main outcomes were hospitalization rates for a diabetes-related foot complication within 30 days of diagnosis and requiring an amputation or death during follow-up. Outcomes were analyzed by regression analysis, accounting for demographics, clinical characteristics, and antibiotic therapy. Results: Among 147 outpatients with infected DFUs, 116 were included. Infections were categorized as mild (68%), moderate (26%), and severe (6%). Empirical antibiotics (not culture-guided) were prescribed as initial treatment in 39 individuals, while 77 received culture-based antibiotics. There were no differences in demographic or clinical characteristics between the antibiotic administration groups, except for a higher body mass index and prevalence of chronic kidney disease in the empirical cohort. Forty-two infected DFU patients required hospitalization within 30 days of diagnosis for the same reason. The relative risk for hospitalizations was 1.87 greater in those with mild infections when treated with empirical antibiotics compared with culture-directed antibiotics. There were no differences in amputations and/or death at 1 year follow-up. Conclusions: These data support obtaining tissue culture to guide antibiotic therapy, regardless of DFU infection severity, to decrease hospitalizations.