Corrected colonisation index over time in patients already colonised at admission to the ICU. Course of the corrected colonisation index (CCI) over time in the treatment group (white bars) and the control group (black bars), considering only patients who were already colonised at admission to the ICU. Illustrated are the daily median values (filled circles), and the 25th and 75th percentiles - that is, the interquartile range (borders of the box). Data in parentheses are the number of patients in each of the two study groups over time. *P < 0.05.