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Accuracy of retrofitted CGM versus number of references available  233




                                  Adults                            Pediatrics
                    15                                 15
                         mean MAD                           mean MAD
                   Mean Absolute Difference [mg/dl]  10 5  Mean Absolute Difference [mg/dl]  10 5









                     0                                 0
                           CGM        Retrofitted CGM         CGM        Retrofitted CGM
                                  Adults                            Pediatrics
                    15                    mean MARD    15                    mean MARD
                   Mean Absolute Relative Difference [%]  10 5  Mean Absolute Relative Difference [%]  10 5










                     0                                 0
                           CGM        Retrofitted CGM         CGM        Retrofitted CGM
                  FIGURE 11.6
                  Boxplot of MAD (top panel) and MARD (bottom panel) population distribution of the
                  original CGM and of the retrofitted CGM obtained with five SMBG per 12-h session (each
                  gray dot represents a patient admission). The improvement granted by the method is
                  clearly visible.

                  references was chosen since it is likely that at least five references in 12 diurnal
                  hours are collected when the CGM sensor is used adjunctively to SMBG, e.g.,
                  two SMBG measurements for calibration plus three SMBG checks around meal
                  time per day. Indeed, five [4,7] SMBGs were collected from 07:00 to 19:00 by
                  the patients in our artificial pancreas studies conducted in free-living conditions
                  for 2 months [27] and 1 month [28]. More precisely, in 59.1% of the 12-h periods
                  going from 07:00 to 19:00 the patients collected five or more SMBGs, and only
                  in 23.8% of these 12-h periods less than four SMBG measurements were performed.



                  Accuracy of retrofitted CGM versus number of references
                  available
                  In this section, we investigate how the accuracy improvement achieved by retrofit-
                  ting Dexcom G5 in real-life conditions is affected by the number of SMBG measure-
                  ments available. In fact, our method leverages on these BG measurements to
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