Vancomycin-resistant Enterococcus colonization in the intensive care unit: Clinical outcomes and attributable costs of hospitalization

BackgroundThe clinical and economic impact of vancomycin-resistant Enterococcus (VRE) colonization remains unclear. Little data are available on factors affecting hospitalization length of stay (LOS) and costs. This study aimed to estimate mortality, LOS, and hospitalization costs for VRE colonized patients compared with a matched hospital population.MethodsWe performed a retrospective propensity score matched cohort study comparing the outcomes of patients with VRE colonization with those of uncolonized subjects matched at the time they were admitted to the intensive care unit (ICU). Between January 2008 and December 2010, we obtained rectal swab cultures within 24 hours of ICU admission to detect VRE colonization.ResultsDuring the study period, 567 (7.2%) of the 7,703 patients were colonized with VRE. There were 199 VRE colonized patients compared with 199 uncolonized patients using the propensity score. VRE colonized patients when compared with uncolonized patients were likely to have a higher case fatality rate (24.6% vs 17.1%; OR, 2.35). Longer total admission days were observed in the VRE colonized patients (28.7 vs 21.4 days; multiplicative effect, 1.25; P = .004). VRE colonization is found to be a significant factor associated with increased ICU cost in the multivariable regression model ($6,065 vs $5,298; multiplicative effect, 1.22; P = .029). Multivariable analysis identified the factors affecting ICU cost as follows: VRE colonization (odds ratio [OR], 1.20; P = .038), ICU length of stay (OR, 1.93; P < .001), ICU type (OR, 1.51; P = .001), valvular heart disease (OR, 2.38; P = .27), hospitalization within 12 months (OR, 1.21; P = .037), and use of invasive devices (OR, 1.28; P = .017).ConclusionCompared with a matched hospital population, VRE colonization was associated with increased mortality, LOS, and costs. Strict infection control programs, including preemptive isolation for a high-risk group, should be helpful.