Clinical and Economic Impact of Methicillin-Resistant Staphylococcus aureus Colonization or Infection on Neonates in Intensive Care Units

Abstract

Objective.The rising incidence and mortality of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection in children has become a great concern. This study aimed to determine the clinical and economic impact of MRSA colonization or infection on infants and to measure excess mortality, length of stay, and hospital charges attributable to MRSA.Design.This is a retrospective cohort study.Setting and Patients.The study included infants admitted to a level III-IV neonatal intensive care unit from September 1, 2004, through March 31, 2008.Methods.A time-dependent proportional hazard model was used to analyze the association between MRSA colonization or infection and mortality. The relationships between MRSA colonization or infection and length of stay and between MRSA colonization or infection and hospital charges were assessed using a matched cohort study design.Results.Of 2,280 infants, 191 (8.4%) had MRSA colonization or infection. Of 132 MRSA isolates with antibiotic susceptibility results, 106 were resistant to clindamycin and/or trimethoprim-sulfamethoxazole, thus representing a noncommunity phenotype. The mortality rate was 17.8% for patients with MRSA colonization or infection and 11.5% for control subjects. Neither MRSA colonization (hazard ratio [HR], 0.9 [95% confidence interval {CI}, 0.5-1.5]; P > .05) nor infection (HR, 1.2 [95% CI, 0.7-1.9]; P > .05) was associated with increased mortality risk. Infection caused by MRSA strains that were resistant to clindamycin and/or trimethoprim-sulfamethoxazole increased the mortality risk by 40% (HR, 1.4 [95% CI, 0.9-2.2]; P > .05), compared with the mortality risk of control subjects, but the increase was not statistically significant. MRSA infection independently increased length of stay by 40 days (95% CI, 34.2—45.6; P < .001) and was associated with an extra charge of $164,301 (95% CI, $158,712-$169,889; P < .001).Conclusions.MRSA colonization or infection in infants is associated with significant morbidity and financial burden but is not independently associated with increased mortality.