Univariate relationships in patient group 1. Univariate relationship (expressed in box plots) between average blood glucose (BG) sampling frequency (f) and glycemic penalty index (GPI) (top panel), duration of algorithm application (D) and GPI (second panel), APACHE II score (A) and GPI (third panel), and type of illness and GPI (bottom panel) based on patient group 1. The p values of the null hypothesis that the GPI medians per group are equal are mentioned in each panel. A significant difference was found for the average BG sampling frequency and the duration of algorithm application. The longer the algorithm is applied to the patient and the longer the time intervals between successive measurements, the tighter the glycemic control (lower GPI). The apparently contradictory impact of the BG sampling frequency on GPI can be explained by the negative correlation between the variables duration of algorithm application and average BG sampling frequency (see text).