This retrospective cohort study included all patients diagnosed
with VAP from April 1, 2007, to May 31, 2010, in the
four adult multidisciplinary intensive care units (ICU) in
AHS-Calgary Zone which care for all critically ill patients
within the city of Calgary and surrounding regions.This time
periodwas chosen to be large enough to include a reasonable
number of cases of VAP yet contemporary enough to reflect
current antibiotic utilization patterns