Epidemiology and Outcomes of Complicated Skin and Soft Tissue Infections in Hospitalized Patients

Abstract

Complicated skin and soft tissue infections (cSSTIs) are among the most rapidly increasing reasons for hospitalization. To describe inpatients with regard to patient characteristics, cSSTI origin, appropriateness of initial antibiotics, and outcomes, we performed a retrospective cohort study in patients hospitalized for cSSTI. To identify independent predictors of outcomes, we performed multivariate analyses. Of 1,096 eligible patients, 48.7% had health care-associated (HCA) cSSTI and 51.3% had community-acquired (CA) cSSTI. After adjustment for baseline variables, hospital length of stay (LOS) was longer for HCA than for CA cSSTI (difference, 2.1 days; 95% confidence interval [CI], 0.8 to 3.5; P < 0.05). Other covariates associated with a longer LOS were need for dialysis (regression coefficient ± standard error, 4.5 ± 1.1) and diabetic wound diagnosis (2.6 ± 1.0) (all P < 0.05). In the subset with culture-positive cSSTI within 24 h of admission, the most common pathogen was Staphylococcus aureus (298/449 [66.4%]), of which 74.8% (223/298) were methicillin-resistant S. aureus (MRSA). Eighty-three patients (18.5%) received inappropriate initial antibiotics. After adjustment for other variables, the following were associated with inappropriate initial therapy: direct admission to hospital (not via emergency department), cSSTI caused by MRSA or mixed pathogens, and cSSTI caused by pathogens other than S. aureus or streptococci (all P < 0.05). We did not find an association between inappropriate therapy and outcomes, except in the subset with ulcers (adjusted odds ratio, 11.8; 95% CI, 1.3 to 111.1; P = 0.03). More studies are needed to examine the impact of HCA cSSTI and inappropriate initial therapy on outcomes.