Statistical analysis
infection
INFECTION
Based on the acquisition rate of CRGNB from 2016 to 2018 in ICUs of our hospital, we assumed a mean baseline incidence of CRGNB colonization or infection of 8 per 1000 patient-days; between-cluster variance would be 0.4, and the average amount of time a patient spent in the ICU would be 10 days. This study was designed to achieve 80% power for detecting a reduction in acquisition of 40% in the intervention period with a 2-sided type I error of 5%. According to these assumptions, the estimated sample size was 2400 patients (200 per cluster; a total of 12 clusters with one cross-over of 6 ICUs) [Categorical variables were analyzed using the chi-square or Fisher’s exact test, as appropriate. Normally and non-normally distributed continuous variables were analyzed by Student’s 