An article has been accepted in the Journal of Diabetes Science and Technology for March which once again will critique the Westgard model of total error. In this case my critique focuses on glucose meters where Boyd and Bruns (1) model glucose meter total error and claim that if one sets goals for (average) bias and imprecision, one knows the total error of glucose meters.
My critique will show (by simulation) that if one has two glucose meters, where one is subject to hematocrit interference and the other not (yes, this happens) that the Boyd and Bruns model fails to distinguish any performance difference between these two meters but a correct way of measuring total error shows that the two meters have much different performance.
One could ask, why write this when I have already critiqued the Boyd and Bruns model and they responded that my critique was correct. The reason is that Boyd and Bruns have written subsequent papers using their model as if my critique never happened. And there is currently much emphasis on understanding how glucose meters perform.
- Boyd JC and Bruns DE Quality Specifications for Glucose Meters: Assessment by Simulation Modeling of Errors in Insulin Dose Clinical Chemistry 2001; 47:209-214.