Prognostic factors in necrotizing soft-tissue infections (NSTI): A cohort study

Background: Necrotizing soft-tissue infection (NSTI) is uncommon but life-threatening. A recent meta-analysis estimated the overall mortality at 23.5%. Objective: We sought to identify risk factors associated with mortality in a cohort of patients with NSTI in a tertiary care center. Methods: We identified 512 patients with NSTI between 1996 and 2012 in the national hospital database Program for Medicalization of Information Systems and examined risk factors of mortality with NSTI by univariate and multivariate analysis. Results: We included 109 patients with a confirmed diagnosis of NSTI; 31 (28%) died at a median follow-up of 274 days (range 2-6135 days). On multivariate analysis, independent risk factors of mortality were age older than 75 years (hazard ratio [HR] 4.4, 95% confidence interval [CI] 1.8-10.3), multifocal NSTI (HR 5.9, 95% CI 1.9-18.5), severe peripheral vascular disease (HR 5.1, 95% CI 1.5-17.0), hospital-acquired infection (HR 3.9, 95% CI 1.4-10.7), severe sepsis (HR 7.4, 95% CI 1.7-33.1), and septic shock on hospital admission (HR 13.9, 95% CI 3.8-50.4). Limitations: This was a retrospective cohort, which disallows a precise record of the delay between diagnosis and surgery. Conclusion: Our findings for this robust cohort of patients with a definite diagnosis of NSTI could help clinicians stratify NSTI severity at clinical course onset.