Performance of a New Test Strip for FreeStyle Blood Glucose Monitoring Systems

Background: A new strip, designed to enhance the ease of use and minimize interference of non-glucose sugars, has been developed to replace the current FreeStyle (R) (Abbott Diabetes Care, Alameda, CA) blood glucose test strip. We evaluated the performance of this new strip. Methods: Laboratory evaluation included precision, linearity, dynamic range, effects of operating temperature, humidity, altitude, hematocrit, interferents, and blood reapplication. System accuracy, lay user performance, and ease of use for finger capillary blood testing and accuracy for venous blood testing were evaluated at clinics. Lay users also compared the speed and ease of use between the new strip and the current FreeStyle strip. Results: For glucose concentrations <75 mg/dL, 73%, 100%, and 100% of the individual capillary blood glucose results obtained by lay users fell within +/- 5, 10, and 15 mg/dL, respectively, of the reference. For glucose concentrations >= 75 mg/dL, 68%, 95%, 99%, and 99% of the lay user results fell within +/- 5%, 10%, 15%, and 20%, respectively, of the reference. Comparable accuracy was obtained in the venous blood study. Lay users found the new test strip easy to use and faster and easier to use than the current FreeStyle strip. The new strip maintained accuracy under various challenging conditions, including high concentrations of various interferents, sample reapplication up to 60 s, and extremes in hematocrit, altitude, and operating temperature and humidity. Conclusions: Our results demonstrated excellent accuracy of the new FreeStyle test strip and validated the improvements in minimizing interference and enhancing ease of use.