Accuracy evaluation of contour next compared with five blood glucose monitoring systems across a wide range of blood glucose concentrations occurring in a clinical research setting.

BACKGROUND: This study evaluated the accuracy of Contour(®) Next (CN; Bayer HealthCare LLC, Diabetes Care, Whippany, NJ) compared with five blood glucose monitoring systems (BGMSs) across a wide range of clinically occurring blood glucose levels. SUBJECTS AND METHODS: Subjects (n=146) were ≥ 18 years and had type 1 or type 2 diabetes. Subjects' glucose levels were safely lowered or raised to provide a wide range of glucose values. Capillary blood samples were tested on six BGMSs and a YSI glucose analyzer (YSI Life Sciences, Inc., Yellow Springs, OH) as the reference. Extreme glucose values were achieved by glucose modification of the blood sample. System accuracy was assessed by mean absolute difference (MAD) and mean absolute relative difference (MARD) across several glucose ranges, with <70 mg/dL evaluated by MAD as the primary end point. RESULTS: In the low glucose range (<70 mg/dL), MAD values were as follows: Accu-Chek(®) Aviva Nano (Roche Diagnostics, Indianapolis, IN), 3.34 mg/dL; CN, 2.03 mg/dL; FreeStyle Lite(®) (FSL; Abbott Diabetes Care, Inc., Alameda, CA), 2.77 mg/dL; OneTouch(®) Ultra(®) 2 (LifeScan, Inc., Milpitas, CA), 10.20 mg/dL; OneTouch(®) Verio(®) Pro (LifeScan, Inc.), 4.53 mg/dL; and Truetrack(®) (Nipro Diagnostics, Inc., Fort Lauderdale, FL), 11.08 mg/dL. The lowest MAD in the low glucose range, from CN, was statistically significantly lower than those of the other BGMSs with the exception of the FSL. CN also had a statistically significantly lower MARD than all other BGMSs in the low glucose range. In the overall glucose range (21-496 mg/dL), CN yielded the lowest MAD and MARD values, which were statistically significantly lower in comparison with the other BGMSs. CONCLUSIONS: When compared with other BGMSs, CN demonstrated the lowest mean deviation from the reference value (by MAD and MARD) across multiple glucose ranges.

Evaluation of a novel continuous glucose measurement device in patients with diabetes mellitus across the glycemic range.

BACKGROUND: This glucose clamp study assessed the performance of an electrochemical continuous glucose monitoring (CGM) system for monitoring levels of interstitial glucose. This novel system does not require use of a trocar or needle for sensor insertion. METHOD: Continuous glucose monitoring sensors were inserted subcutaneously into the abdominal tissue of 14 adults with type 1 or type 2 diabetes. Subjects underwent an automated glucose clamp procedure with four consecutive post-steady-state glucose plateau periods (40 min each): (a) hypoglycemic (50 mg/dl), (b) hyperglycemic (250 mg/dl), (c) second hypoglycemic (50 mg/dl), and (d) euglycemic (90 mg/dl). Plasma glucose results obtained with YSI glucose analyzers were used for sensor calibration. Accuracy was assessed retrospectively for plateau periods and transition states, when glucose levels were changing rapidly (approximately 2 mg/dl/min). RESULTS: Mean absolute percent difference (APD) was lowest during hypoglycemic plateaus (11.68%, 14.15%) and the euglycemic-to-hypoglycemic transition (14.21%). Mean APD during the hyperglycemic plateau was 17.11%; mean APDs were 18.12% and 19.25% during the hypoglycemic-to-hyperglycemic and hyperglycemic-to-hypoglycemic transitions, respectively. Parkes (consensus) error grid analysis (EGA) and rate EGA of the plateaus and transition periods, respectively, yielded 86.8% and 68.6% accurate results (zone A) and 12.1% and 20.0% benign errors (zone B). Continuous EGA yielded 88.5%, 75.4%, and 79.3% accurate results and 8.3%, 14.3%, and 2.4% benign errors for the euglycemic, hyperglycemic, and hypoglycemic transition periods, respectively. Adverse events were mild and unlikely to be device related. CONCLUSION: This novel CGM system was safe and accurate across the clinically relevant glucose range.

Accuracy and utility of a 10-test disk blood glucose meter.

We evaluated the clinical accuracy, precision, and ease-of-use of a whole blood referenced glucose meter system that uses a 10-test disk (Ascensia Confirm Blood Glucose Monitoring System, Bayer Healthcare LLC). The meter system was tested by 100 subjects and eight health care professionals at two separate diabetes centers. Meter blood glucose test results, obtained by the subjects and health care professionals, were accurate and correlated well when compared with laboratory results. The means of the subject and healthcare professional blood glucose results were within 4.8% of the laboratory mean glucose result. When compared with laboratory results, the correlation coefficient was 0.96 for subject meter results and 0.97 for health care professional meter results. Error grid analyses demonstrated that all subject and health care professional blood glucose measurements fell within zones A and B ('no effect on clinical action' and 'altered clinical action with little or no effect on clinical outcome,' respectively). Ninety-three percent (93%) of subjects rated the meter system favorably on an 'ease-of-use' questionnaire. A majority of subjects correctly performed blood glucose self-monitoring tasks simply by reviewing the user guide. In summary, this unique meter that uses a 10-test disk was shown to be both accurate and precise, and subjects with diabetes were able to use the system properly with minimal instructions.

The clinical performance and ease of use of a blood glucose meter that uses a 10-test disk.

Patient and health care provider evaluations are critical in establishing the accuracy and usability of new blood glucose meter systems. The objective of our study was to evaluate the clinical performance and ease of use of a blood glucose meter that uses a 10-test disk (Ascensia Breeze meter system, Bayer Healthcare LLC, Elkhart, IN). Meter capillary blood glucose results were compared with laboratory glucose results from 100 subjects with diabetes at two diabetes centers. Five health care professionals also tested subject blood samples. The subjects completed a questionnaire rating the ease of use of the meter, and their ability to learn to use the meter was also evaluated. Analytical accuracy of the meter system was assessed using ISO 15197:2003 performance criteria. Subject and health care professional meter glucose results were within 20% of laboratory glucose results [or 15 mg/dL (0.83 mmol/L) for specimens with less than 75 mg/dL (4.17 mmol/L) glucose levels] for 93.4% and 94.4% of results, respectively. Clinical accuracy of the system was evaluated using Parkes error grid analysis. The error grid analyses showed that 100% of subject and health care professional meter blood glucose results were in Zones A (92%) and B (8%). In the ease-of-use questionnaire, 91% of subject ratings of the meter were favorable. Subjects learned to operate the meter properly using the meter instructional material with little or no assistance from the health care professionals. The 10-test disk was rated as a prominent favorable feature. The new meter was accurate and precise in the hands of subjects with diabetes and health care professionals. Subjects found the meter easy and intuitive to learn to use. The study subjects were able to correctly use the meter after independently reviewing the user guide.