Staphylococcus aureus Colonization before Infection Is Not Associated with Mortality among S. aureus-Infected Patients: A Meta-analysis

BACKGROUND AND OBJECTIVE. The literature is conflicted as to whether people colonized with Staphylococcus aureus are at an increased risk of mortality. The aim of this meta-analysis was to review and analyze the current literature to determine whether prior history of S. aureus colonization is associated with mortality among S. aureus-infected patients. METHODS. The PUBMED databases were searched with keywords related to S. aureus colonization and mortality. After reviewing 380 article abstracts and 59 articles in detail, only 7 studies had data on the association between S. aureus colonization and mortality among S. aureus-infected patients. Crude estimates of study odds ratios (ORs) were calculated on the basis of data from subset analyses. We pooled crude ORs from the 7 studies using a random-effects model. Woolf's test for heterogeneity was assessed. RESULTS. When all studies were pooled in a random-effects model, no association between S. aureus colonization and mortality among S. aureus-infected patients was seen (pooled OR, 1.08 [95% confidence interval (CI), 0.32-3.66]; n = 7; heterogeneity P = .05). When the analyses were restricted to infection-attributable mortality, the association between colonization and mortality among S. aureus-infected patients was not statistically significant (pooled OR, 0.42 [95% CI, 0.15-1.21]; n = 4; heterogeneity P = .28). CONCLUSIONS. S. aureus colonization was not associated with mortality among patients who developed an S. aureus infection. Interventions to decolonize S. aureus carriers may prevent S. aureus infections but may not be sufficient to prevent mortality. Infect Control Hosp Epidemiol 2012;33(8):796-802