343-50Objective. To evaluate risk factors associated with methicillin-resistant Staphylococcus
aureus (MRSA) bacteremia emergence, its prognosis, and mortality-determining factors in
critically ill patients in Colombia.
Methods. A multicenter, retrospective cohort study conducted in 2005–2008 at 16 public
and private reference health care institutions in Bogotá, Colombia, that form part of a national
epidemiological surveillance network and a hospital network with 4 469 beds. Methicillinresistant
emergence and mortality were analyzed using descriptive and time-to-event analysis;
a multivariate Cox proportional hazard regression model was built to test the association
between methicillin resistance and mortality.
Results. A total of 372 patients were studied: 186 with MRSA bacteremia, randomly
matched with 186 with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia.
Previous surgery, antibiotic exposure, and hospital-acquired infections were independently
associated with methicillin resistance. MRSA caused longer hospital stays among survivors
(median 24 versus 18 days, P = 0.014). Mortality predictors were: patient age, creatinine
level over 1.21mg/dl at ICU admission, severe sepsis, and inotropic requirement. Appropriate
antimicrobial therapy and antimicrobial therapy change were independent protective factors,
as was male gender.
Conclusions. Methicillin resistance per se was not a mortality-independent prognostic
factor. Previous conditions, such as age, baseline renal impairment, severe sepsis, and inotropy
demand explained the observed mortality. Appropriate antimicrobial therapy remained a
protective factor. A call to improve infection control measures in Colombia is mandatory
