Skin and soft-tissue infections: Factors associated with mortality and re-admissions

Skin and soft-tissue infections (SSTIs) are common and are linked to a wide variety of clinical conditions. Few studies have analysed the factors associated with mortality and re-admissions in medical patients with SSTIs. Accordingly, this study sought to describe the clinical and microbiological characteristics of patients diagnosed with SSTIs, and identify mortality and re-admission related factors.

A total of 308 patients were included in the study. Clinical, socio-demographic and microbiological characteristics were collected. Univariate and logistic regression multivariate analyses were performed in order to identify factors associated with mortality and re-admission.

The bacteria responsible were identified in 95 (30.8%) patients, with gram-positive bacteria being isolated in 67.4% and gram-negative in 55.8% of cases. Multi-resistant bacteria were frequent (39%), and the initial empirical treatment proved inadequate in 25.3% of all cases. In-hospital mortality was 14.9%; the related variables were heart failure (OR=5.96; 95%CI: 1.93-18.47), chronic renal disease (OR=6.04; 95%CI: 1.80-20.22), necrotic infection (OR=4.33; 95%CI: 1.26-14.95), and inadequate empirical treatment (OR=44.74; 95%CI: 5.40-370.73). Six-month mortality was 8%, with the main related factors being chronic renal disease (OR: 3.03; 95%CI: 1.06-8.66), and a Barthel Index score of under 20 (OR: 3.62; 95%CI: 1.17-11.21). Re-admission was necessary in 26.3% of cases, with the readmission-related variables being male gender (OR: 2.12; 95%CI: 1.14-3.94), peripheral vascular disease (OR: 3.05; 95%CI: 1.25-7.41), and an age-adjusted Charlson Comorbidity Index score of over 3 (OR: 3.27; 95%CI: 1.40-7.63).

Clinical variables such as heart failure, chronic renal disease, peripheral vascular disease, and necrotic infection could help identify high-risk patients. The main factor associated with higher mortality was inadequate initial empirical treatment. Physicians should consider gram-negative, and even extended-spectrum beta-lactamase-producing bacteria when assigning initial empirical treatment for SSTIs, especially in healthcare-associated cases.