Assessing System Accuracy of Blood Glucose Monitoring Systems Using Rectangle Target Plots

Background: Results from accuracy assessments of systems for self-monitoring of blood glucose (SMBG) are often visualized in difference or regression plots. These approaches become more difficult to read as the number of data points displayed increases, thus limiting their use. In the recently presented rectangle target plot (RTP) approach, data from each reagent system lot or product are displayed graphically as a single rectangle, thus allowing the plot to remain comprehensible even when displaying system accuracy data from multiple reagent system lots or products. Methods: The RTP illustrates the accuracy of SMBG systems. Each rectangle shows the mean bias and the variability of a system. By use of statistical tolerance intervals, each rectangle most closely approximates the total error for lower (