Characteristics of Patients Hospitalized for Acute Bacterial Skin and Skin Structure Infections (ABSSSI) From 2009 to 2013

Background. Acute bacterial skin and skin structure infections (ABSSSIs) are a common cause of hospitalization in the United States. This study aimed to characterize the patient population hospitalized for ABSSSI, including comorbidities, pathogens identified, and length of initial inpatient stay. Methods. Adults (>18 years) hospitalized with ≥1 primary ABSSSI diagnosis were selected from the Cerner Health Facts electronic medical records database (2009–2013). Typical causative pathogens for ABSSSI and Gram stain type (positive or negative) were identified from microbiology culture. In addition, patients with methicillin-resistant Staphylococcus aureus (MRSA) were also identified. Patients without culture results were classified as “Unknown”. Length of initial inpatient stay (measured from admission to discharge) was compared between the cohorts with and without MRSA infections descriptively. Results. A total of 11,705 patients were identified: 51.8% were male, mean age was 55 years at admission, and 31.3% were ≥65 years old. A total of 49.7% of the patients were obese, 30.9% were diabetic, 48.9% were hypertensive, and 12.4% were diagnosed with depression. Over half (56.6%) of the patients had no culture results. Of the patients that had an identified ABSSSI-causing pathogen, 63.9% were Gram-positive, including 18.4% infected with MRSA. A total of 11.9% were Gram-negative, and 24.2% were mixed infections (Gram-positive and negative), including 3.6% with MRSA. Mean length of stay was higher for patients with MRSA infections than those without MRSA (7.1 versus 6.4 days, p = 0.0009). Conclusion. Hospitalized patients with ABSSSI have a number of comorbidities, including obesity, diabetes, hypertension, and depression which can complicate antibiotic selection. Over half of the patients did not have a pathogen identified; when identified 21.9% involved MRSA, and 24.2% were mixed infections (including MRSA). Patients with a MRSA infection experienced longer length of stay. Patient characteristics and pathogen coverage should be considered in antibiotic selection in ABSSSI. Disclosures. E. Mcginnis, Melinta Therapeutics, Inc.: Employee, Salary; S. Cammarata, Melinta Therapeutics: Employee, Salary; R. D. Tan, Analysis Group, Inc.: Employee, Salary; M. Barrett, Analysis Group, Inc.: Employee, Salary; E. Tuttle, Analysis Group, Inc.: Employee, Salary