Figure 2
From: Continuous glucose monitors prove highly accurate in critically ill children
Clarke error grid and Bland-Altman agreement analysis of paired BG readings. A total of 1,555 CGM values from 47 pediatric ICU patients were compared for agreement with BG measurements (A). In Clarke plots (upper panel), the routine POC readings (X-axis) were compared to corresponding CGM values (Y-axis). Readings in Zone A differ by ≤20%, whereas those in Zone B differ by >20% but do not impact management. The Zone A + B composite is considered "clinically acceptable" correlation. Zone C values would lead to therapeutic overcorrection and Zone D readings would not trigger intervention, although warranted. Zone E values would result in treatment aggravating a hypo- or hyperglycemic state. In Bland-Altman analysis (bottom panel), the mean of the paired readings is on the X-axis, and the difference is on the Y-axis. The broken line represents the cutoff of two standard deviations from the mean difference. In addition to the R2, the solid line with the indicated slope is shown and represents the correlation coefficient. Clarke and Bland-Altman plots are shown for patient subpopulations less than one-year-old (B), those who received vasopressor or inotropic support (C), and those who developed critical illness hyperglycemia and were managed with insulin using our protocol (D).