Longer duration of hospitalization was significantly associated with any bacterial pneumonia only in univariate analysis (OR 1.07, 95% CI 1.02–1.12, p = 0.004), while there was no significant association between age, sex, Charlson comorbidity index, prior smoking, albumin, or glucose and bacterial VAP (Table 4). This evidence concerns the gene ALB and ventilator-associated pneumonia.