 Consecutive adult patients age 18 years who were admitted to the mixed medical-surgical ICUs 72 hours and received invasive ventilation 48 hours were enrolled and monitored daily for the development of ventilator-associate pneumonia VAP until ICU discharge or death. Patients with any limitation of code status were excluded from the study. Convenience sample of critical care nurses were recruited through letters and telephone and face-to-face invitations. Inclusion criteria were holding a degree qualification as a registered nurse and being a direct care provider bedside. Nurses with less than one year experience in critical care unit or working less than whole study period were excluded. An investigator at each participating medical center was responsible for initial screening and enrollment. 