A new, improved test system for rapid measurement of blood glucose

Several models of blood glucose meters are available to diabetic patients. They all require several steps for their operation, which increases the potential for user error. A new meter (One Touch TM System, Lifescan Inc., a Johnson & Johnson Company, Mountain View, CA) was designed to minimise the operational steps and therefore increase reliability. This system was compared for precision, accuracy and clinical safety to the Yellow Spring Instrument (YSI) Model 23A Glucose Analyser (Yellow Springs, OH) in 20 diabetic subjects. Good precision was demonstrated by the coefficient of variation (CV%) in 20 tests performed by each subject on a single heparinised specimen of their own venous blood. The CV was 4.5% (range 1.8-10.4). Accuracy was determined by the regression of the mean of the glucose results corrected for glycolysis compared to the mean YSI result. The regression line had a slope of 1.02, a Y intercept at -4.21 mg/dl, a correlation coefficient (r) of 0.999 (P less than 0.001) and a root mean square % (RMS) error of 4.385. Clinical safety was demonstrated by error grid analysis in which 399 of 400 tests fell in the clinically safe range, and reading error analysis in which two of 400 tests fell more than 25% from the reference method. It is concluded that the One Touch system has good accuracy when compared with the YSI method, is easier to use than the presently available meters, and is a useful addition to the management of diabetes in patients who perform self-monitoring of blood glucose.