BACKGROUND:Recent changes in critical care delivery, including the widespread implementation of health-care bundles, were aimed at reducing complications of critical illness, in particular ventilator-associated pneumonia (VAP), but no population-based study evaluated its effectiveness. METHODS:Using a previously validated electronic medical record database, we identified adult (≥ 18 years old) critically ill patients from Olmsted County, Minnesota, requiring mechanical ventilation for ≥ 48 h from January 2003 to December 2009. Trained intensivists identified cases of VAP according to different established clinical definitions. The incidence and outcome of VAP was compared before and after implementation of the so-called "VAP bundle." RESULTS:The median age, severity of illness, proportion of surgical patients, and patients with neurologic disease increased over time (P < .05 for trend in all). Regardless of the definition used, the VAP rate remained similar throughout the study period and did not change with the introduction of the VAP bundle. According to previous Centers for Disease Control and Prevention criteria, the yearly estimates of the VAP incidence ranged between 7.1 and 10.4 cases per 1,000 ventilator-days, with an age-adjusted incidence of 3.1 vs 5.6 per 100,000 population (P = .54 for trends). Standardized hospital mortality ratio of patients at high risk to develop VAP significantly decreased from 1.7 (95% CI, 0.8-3.0) to 0.7 (95% CI, 0.3-1.4; P = .0003 for trend). CONCLUSIONS:The incidence of VAP was unaffected by the implementation of the VAP bundle. Secular changes in hospital mortality are unlikely to be attributed to the VAP bundle per se.