RESUMEN

BACKGROUND: The accuracy of blood glucose monitoring systems (BGMS) is crucial for the safe and effective management of diabetes mellitus. Despite standardization of accuracy assessment procedures and requirements, various studies have shown that the accuracy of BGMS on the market can vary considerably. This article therefore provides health care professionals and users with an intuitive illustration of the impact of BGMS accuracy on clinical decision making. MATERIAL AND METHODS: Several hypothetical patient scenarios based on blood glucose (BG) levels in the low, normal, and high BG range are devised. Using data from a recent BGMS accuracy study, a method for calculating the expected range of BG readings from four examined BGMS at the selected BG levels is introduced. Based on these ranges, it is illustrated how clinical decisions and subsequent outcomes of the hypothetical patients are affected by the expected inaccuracies of the BGMS. RESULTS: The range of expected BGMS readings for the same true BG level can vary considerably between different BGMS. The discussion of hypothetical patient scenarios revealed that the use of some BGMS could be associated with an increased risk of adverse events such as failure to detect hypoglycemia, driving with an unsafe BG level, delay of treatment intervention in diabetes during pregnancy, or the failure to prevent diabetic ketoacidosis. CONCLUSIONS: This article can support both health care professionals and patients to understand the impact of BGMS accuracy in a relatable, clinical context. Furthermore, it is suggested that current accuracy requirements might be insufficient for the prevention of adverse clinical outcomes in certain circumstances.

Asunto(s)

RESUMEN

Objective: To perform evaluations of the CONTOUR PLUS LINK 2.4 blood glucose monitoring system (BGMS) assessed according to ISO 15197:2013 criteria.Methods: Clinical trial registered at ClinicalTrials.gov (NCT01824355). In a laboratory study (Study 1), capillary fingertip blood samples from 100 subjects were evaluated in duplicate, using three test strip lots. In a clinical trial (Study 2), 113 adults with diabetes were enrolled, and BGMS results and Yellow Springs Instruments (YSI) analyzer reference measurements were compared for subject- and trial staff-obtained fingertip blood and subject-obtained palm blood. Subjects completed a questionnaire to evaluate BGMS ease of use.Results: In Study 1, 100% of combined results (all test strip lots) fulfilled ISO 15197:2013 section 6.3 criteria. In Study 2, 97.7% of subject-obtained fingertip results and 100% of trial staff-obtained fingertip results met ISO 15197:2013 section 8 criteria. Additionally, 93.8% of palm results were within ± 15 mg/dL of mean YSI measurements for glucose concentrations <100 mg/dL or ± 15% for glucose concentrations ≥100 mg/dL. Most subjects found the BGMS easy to use. There were three non-serious, non-device related adverse events.Conclusion: The BGMS exceeded minimum ISO 15197:2013-specified accuracy criteria in the laboratory and in the hands of lay users with diabetes.

Asunto(s)

RESUMEN

Aim: Inaccurate blood glucose monitoring system (BGMS) results may lead to insulin dosing errors and adverse clinical outcomes. Results & methodology: This post-hoc analysis used a model to estimate the bolus insulin dose error associated with each of the five BGMSs, for a hypothetical person with diabetes (assuming a standardized meal and target blood glucose of 100 mg/dl). Differences in dose-error distribution between BGMSs were statistically tested. The 95% dose-error range for each BGMS was (insulin units): CONTOUR®PLUS, -1.1-0.7; Accu-Chek® Active, -2.4-0.7; Accu-Chek® Performa, -2.9-0.8; FreeStyle Freedom, from -5.5 to -0.5; OneTouch® SelectSimple™, -4.1-3.0. Conclusion: The CONTOUR®PLUS BGMS was associated with a statistically significantly smaller model-estimated median bolus insulin dose-error and dosing error range, compared with the other BGMSs.

Asunto(s)

RESUMEN

Aim: The radar plot is a relatively new way of communicating blood glucose monitoring system (BGMS) accuracy and precision: data points positioned within concentric circles represent the magnitude (increasing with distance from center) and direction (relative to horizontal) of BGMS-error (center = equivalency with reference instrument measurement). This manuscript aims to demonstrate the utility of radar plots as visual tools for interpretation of BGMS analytical performance. Results & methodology: Radar plots were constructed for five BGMSs, to compare BGMS blood glucose results with reference instrument measurements. Conclusion: Radar plots are a useful tool for the visualization of BGMS analytical performance, communicating accuracy, precision and the satisfaction of certain regulatory criteria at a glance.

Asunto(s)

RESUMEN

BACKGROUND: Diabetes treatment is intended to maintain near-normal glycemic levels. Self-monitoring of blood glucose (SMBG) allows patients to track their BG levels compared with glycemic targets and is associated with improved health outcomes. Because of the importance of SMBG, it is essential that results are accurate to prevent errors in nutritional intake and drug dosing. This study presents a new methodology to evaluate the accuracy of BG monitoring systems (BGMSs). METHODS: Sensitivity analyses were performed using real and simulated BGMS data to compute probabilities that, for any BG value, the BGMS result would be within prescribed error bounds and confidence limits compared with laboratory reference values. Multiple BG value ranges were used. RESULTS: Probability curves were created using data from 3 simulated BGMSs and anonymized data from 3 real-world BGMSs. Accuracy probability curves from capillary fingertip blood samples (actual clinical data) showed that all 3 real-world BGMSs met EN ISO 15197:2015 accuracy criteria, since 99.63%, 99.63%, and 99.81% of results from the 3 BGMSs were within ±15 mg/dL or ±15% of reference for BG <100 mg/dL and ≥100 mg/dL, respectively. However, there was identifiable variability between BGMSs if BG was <70 mg/dL; one BGMS showed further reductions in accuracy if BG was <50 mg/dL. CONCLUSIONS: Probability curves highlight the importance of BGMS accuracy to help achieve optimal glycemic control while avoiding hypoglycemia or hyperglycemia. This may be especially significant in very low BG ranges where small errors in BGMS measurements can have substantial impacts on patient-related outcomes, including hypoglycemia risk.

Asunto(s)

RESUMEN

BACKGROUND: These studies investigated the accuracy of the new Contour®Next ONE blood glucose monitoring system (BGMS) that is designed to sync with the Contour™ Diabetes app on a smartphone or tablet. METHODS: A laboratory study tested fingertip capillary blood samples from 100 subjects in duplicate using 3 test strip lots, based on ISO 15197:2013 Section 6.3 analytical accuracy standards. A clinical study assessed accuracy per ISO 15197:2013 Section 8 criteria. Subjects with (n = 333) or without (n = 43) diabetes and who had not used the BGMS previously were enrolled. Each subject performed a self-test using the BGMS, which was repeated by a site staff member. Alternate site tests and venipunctures were also performed for analysis. A questionnaire was provided to assess user feedback on ease of use. RESULTS: In the laboratory study, 100% (600/600) of combined results for all 3 test strip lots met ISO 15197:2013 Section 6.3 accuracy criteria. In the clinical study, among subjects with diabetes, 99.4% (327/329) of subject self-test results, 99.7% (331/332) of results obtained by study staff, 97.2% (309/318) of subject palm results, and 100% (330/330) of venous results met ISO 15197:2013 Section 8 accuracy criteria. Moreover, 97.6% (321/329) of subject self-test results were within ±10 mg/dl (±0.6 mmol/L) or ±10% of the YSI reference result. Questionnaire results indicated that most subjects considered the system easy to use. CONCLUSIONS: The BGMS exceeded ISO 15197:2013 accuracy criteria in the laboratory and in a clinical setting.

Asunto(s)

RESUMEN

BACKGROUND: The new Contour®Plus ONE blood glucose monitoring system (BGMS) features an easy-to-use, wireless-enabled blood glucose meter that links to a smart mobile device via Bluetooth® connectivity and can sync with the Contour™ Diabetes app on a smartphone or tablet. METHODS: The accuracy of the new BGMS was assessed in 2 studies according to ISO 15197:2013 criteria. In Study 1 (laboratory study), fingertip capillary blood samples from 100 subjects were tested in duplicate using 3 test strip lots. In Study 2 (clinical study), 134 subjects with type 1 or type 2 diabetes enrolled at 2 clinical sites. BGMS results and YSI analyzer (YSI) reference results were compared for fingertip blood obtained by untrained subjects' self-testing and for study staff-obtained fingertip, subject palm, and venous results. RESULTS: In Study 1, 99.0% (594/600) of combined results for all 3 test strip lots fulfilled ISO 15197:2013 Section 6.3 accuracy criteria. In Study 2, 99.2% (133/134) of subject-obtained capillary fingertip results, 99.2% (133/134) of study staff-obtained fingertip results, 99.2% (125/126) of subject-obtained palm results, and 100% (132/132) of study staff-obtained venous results met ISO 15197:2013 Section 8 accuracy criteria. Moreover, 95.5% (128/134) of subject-obtained fingertip self-test results were within ±10 mg/dl (±0.6 mmol/L) or ±10% of the YSI reference result. Questionnaire results showed that most subjects found the BGMS easy to use. CONCLUSIONS: The BGMS exceeded ISO 15197:2013 accuracy criteria both in the laboratory and in a clinical setting when used by untrained subjects with diabetes.

Asunto(s)

RESUMEN

BACKGROUND: In 2 previous clinical trials, fingertip capillary blood samples were evaluated using prespecified blood glucose monitoring systems (BGMSs) and a reference YSI glucose analyzer. In post hoc analyses, hypothetical insulin doses were calculated using these blood glucose measurements; dosing errors were compared for each trial. METHOD: For each blood glucose measurement, premeal bolus insulin dosing was determined for a hypothetical person, assuming a 60-g carbohydrate meal and 100-mg/dL target blood glucose level (adjusting 1/25 insulin sensitivity and 1/15 insulin:carbohydrate ratio inputs to account for BGMS measurement error). Dosing error was the difference between doses calculated using the BGMS and YSI results. RESULTS: In Clinical Trial 1, 95% dose error ranges (in units of insulin) were: CONTOUR®NEXT EZ BGMS (EZ), -0.9 to 0.5; Accu-Chek® Aviva BGMS (ACA), -0.5 to 1.8; FreeStyle Freedom Lite® BGMS (FFL), -3.2 to -0.3; OneTouch® Ultra®2 BGMS (OTU2), -4.1 to 0.3; and Truetrack® BGMS (TT), -3.9 to 2.2. In Clinical Trial 2, these ranges were: CONTOUR®NEXT BGMS (CN), -0.7 to 1.7; Accu-Chek® Aviva Nano BGMS (ACAN), -1.3 to 1.8; FreeStyle Lite® BGMS (FSL), -5.1 to 0.2; OTU2, -1.9 to 1.2; OneTouch® Verio® Pro BGMS (OTVP), -1.0 to 1.9; and TT, -5.1 to 1.7. Within each trial, EZ and CN had statistically significantly smaller insulin dose error ranges than other BGMSs ( P <0.0001). CONCLUSIONS: The ranges of insulin dose errors were statistically significantly smaller with EZ and CN than with all other BGMSs in this post hoc analysis. Differences in BGMS accuracy could result in clinically important differences in insulin dosing.

Asunto(s)

RESUMEN

BACKGROUND: Previously, fingertip capillary blood glucose measurements from the CONTOUR®NEXT (CN) blood glucose monitoring system (BGMS) and 5 other BGMSs were evaluated in comparison with measurements from a reference YSI glucose analyzer. Here, we use Radar Plots to graphically represent the accuracy and precision results from the previous study, including whether they met ISO 15197:2013 accuracy criteria. METHOD: A Radar Plot, a new method for capturing a distinct, single visualization of BGMS analytical performance, is a collection of concentric circles, each representing a particular magnitude of error. The center of the plot represents zero error (BGMS result is equivalent to reference result); as points are more distant from the center, the error increases, expressed in units of mg/dL or percentage for YSI values <100 and ≥100 mg/dL, respectively. The position of the data point above or below the horizontal line bisecting the plot indicates whether the BGMS measurement error was positive (BGMS result > YSI result) or negative (BGMS result < YSI result). Points within the "15-15 Zone," representing ±15 mg/dL or ±15% error, satisfy ISO 15197:2013 accuracy criteria. RESULTS: The percentage of results within the 15-15 Zone ranged from 83.6% to 99.8% for the 6 BGMSs (99.6% for CN). CONCLUSIONS: Radar Plots provide a different method for visually comparing the analytical performance of multiple BGMSs. The tight clustering of data points at the center of the CN Radar Plot illustrates the analytical performance of CN compared with 5 other BGMSs.

Asunto(s)

RESUMEN

The relationship between International Organization for Standardization (ISO) accuracy criteria and mean absolute relative difference (MARD), 2 methods for assessing the accuracy of blood glucose meters, is complex. While lower MARD values are generally better than higher MARD values, it is not possible to define a particular MARD value that ensures a blood glucose meter will satisfy the ISO accuracy criteria. The MARD value that ensures passing the ISO accuracy test can be described only as a probabilistic range. In this work, a Bayesian model is presented to represent the relationship between ISO accuracy criteria and MARD. Under the assumptions made in this work, there is nearly a 100% chance of satisfying ISO 15197:2013 accuracy requirements if the MARD value is between 3.25% and 5.25%.

Asunto(s)

RESUMEN

This study assesses and demonstrates that CONTOUR® XT-BGMS (CXT-BGMS) complies with the requirements of the German (RiliBÄK) and Swiss (QUALAB) quality control guidelines for point-of-care testing (POCT) and fulfills the ISO15197:2013 accuracy limits criteria under the routine conditions of a hospital point-of care setting. This single-center study was conducted in Switzerland using 105 venous blood samples from hospitalized patients. Each sample was tested in comparison to the hexokinase reference method. Compliance with POCT guidelines was assessed by daily BGMS measurements using control solutions. Accuracy of CXT-BGMS according to ISO limits was 98.41%. All control measurements were within the limits defined by RiliBÄK (within ± 11% of target values and root mean square error [RMSE] within RMSE limits), and QUALAB (within ± 10% of target values).

Asunto(s)

RESUMEN

BACKGROUND: As blood glucose monitoring system (BGMS) accuracy is based on comparison of BGMS and laboratory reference glucose analyzer results, reference instrument accuracy is important to discriminate small differences between BGMS and reference glucose analyzer results. Here, we demonstrate the important role of reference glucose analyzer accuracy in BGMS accuracy evaluations. METHODS: Two clinical studies assessed the performance of a new BGMS, using different reference instrument procedures. BGMS and YSI analyzer results were compared for fingertip blood that was obtained by untrained subjects' self-testing and study staff testing, respectively. YSI analyzer accuracy was monitored using traceable serum controls. RESULTS: In study 1 (N = 136), 94.1% of BGMS results were within International Organization for Standardization (ISO) 15197:2013 accuracy criteria; YSI analyzer serum control results showed a negative bias (-0.64% to -2.48%) at the first site and a positive bias (3.36% to 6.91%) at the other site. In study 2 (N = 329), 97.8% of BGMS results were within accuracy criteria; serum controls showed minimal bias (<0.92%) at both sites. CONCLUSIONS: These findings suggest that the ability to demonstrate that a BGMS meets accuracy guidelines is influenced by reference instrument accuracy.

Asunto(s)

RESUMEN

BACKGROUND: Blood glucose monitoring is an essential component of diabetes management. Inaccurate blood glucose measurements can severely impact patients' health. This study evaluated the performance of 3 blood glucose monitoring systems (BGMS), Contour® Next USB, FreeStyle InsuLinx®, and OneTouch® Verio™ IQ, under routine hospital conditions. METHODS: Venous blood samples (N = 236) obtained for routine laboratory procedures were collected at a Spanish hospital, and blood glucose (BG) concentrations were measured with each BGMS and with the available reference (hexokinase) method. Accuracy of the 3 BGMS was compared according to ISO 15197:2013 accuracy limit criteria, by mean absolute relative difference (MARD), consensus error grid (CEG) and surveillance error grid (SEG) analyses, and an insulin dosing error model. RESULTS: All BGMS met the accuracy limit criteria defined by ISO 15197:2013. While all measurements of the 3 BGMS were within low-risk zones in both error grid analyses, the Contour Next USB showed significantly smaller MARDs between reference values compared to the other 2 BGMS. Insulin dosing errors were lowest for the Contour Next USB than compared to the other systems. CONCLUSIONS: All BGMS fulfilled ISO 15197:2013 accuracy limit criteria and CEG criterion. However, taking together all analyses, differences in performance of potential clinical relevance may be observed. Results showed that Contour Next USB had lowest MARD values across the tested glucose range, as compared with the 2 other BGMS. CEG and SEG analyses as well as calculation of the hypothetical bolus insulin dosing error suggest a high accuracy of the Contour Next USB.

Asunto(s)

RESUMEN

BACKGROUND: Self-monitoring of blood glucose is crucial for the effective self-management of diabetes. The present study evaluated the accuracy of the Contour® XT blood glucose monitoring system (BGMS) compared to the reference method in a large multicenter study under routine lab conditions at each hospital site. METHODS: This study was conducted at 21 leading hospitals in Spain using leftover whole blood samples (n = 2100). Samples were tested with the BGMS using 1 commercial strip lot and the local laboratory hexokinase method. BGMS accuracy was assessed and results were compared to ISO 15197:2013 accuracy limit criteria and by using mean absolute relative difference analysis (MARD), consensus (Parkes) error grid (CEG), and surveillance error grid analyses (SEG). RESULTS: Pooled analysis of 2100 measurements from all sites showed that 99.43% of the BGMS results were within the ranges accepted by the accuracy limit criteria. The overall MARD was 3.85%. MARD was 4.47% for glucose concentrations < 70 mg/dL and 3.81% for concentrations of 70-300 mg/dL. In CEG, most results (99.8%) were within zone A ("no effect on clinical action"); the remaining ones (0.2%) were in zone B ("little to no effect on clinical action"). The SEG analysis showed that most of the results (98.4%) were in the "no risk" zone, with the remaining results in the "slight, lower" risk zone. CONCLUSIONS: This is the largest multicenter study of Contour XT BGMS to date, and shows that this BGMS meets the ISO 15197:2013 accuracy limit criteria under local routine conditions in 21 leading Spanish hospitals.

Asunto(s)

RESUMEN

INTRODUCTION: The aim of this study was to compare the accuracy of 5 blood glucose monitoring systems (BGMSs; CONTOUR(®)PLUS [CP], Accu-Chek(®) Active [ACA], Accu-Chek(®) Performa [ACP], FreeStyle Freedom™ [FF], OneTouch(®) SelectSimple™ [OTSS]). METHODS: Study staff tested fingerstick samples from 106 subjects aged ≥18 years using the 5 BGMSs. Some samples were modified to achieve blood glucose concentrations throughout the measuring range. The primary endpoint was comparison of the mean absolute relative difference (MARD) from the reference value (Yellow Springs Instruments [YSI]) across the overall tested glucose range. Other endpoints were MARD in the low (≤80 mg/dL [≤4.4 mmol/L]), middle (81-180 mg/dL [4.5-10.0 mmol/L]), and high (>180 mg/dL [>10.0 mmol/L]) glucose ranges, and MARD for unmodified samples in the overall glucose range. RESULTS: CONTOUR(®)PLUS had a statistically significantly lower MARD than all BGMSs across the overall tested range (27-460 mg/dL [1.5-25.5 mmol/L]) and in the high glucose range. In the low glucose range, CP had a lower MARD than all BGMSs, which was statistically significant except for ACP. For unmodified samples across the overall tested range, CP had a lower MARD than all BGMSs and was statistically significantly lower except for ACA. CONCLUSIONS: CONTOUR(®)PLUS had the lowest mean difference from the reference values (by MARD) when compared with other BGMSs across multiple glucose ranges with modified and unmodified samples. FUNDING: Bayer HealthCare LLC, Diabetes Care. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier NCT01714232.

RESUMEN

BACKGROUND: The Contour(®) Next Link 2.4 blood glucose monitoring system (BGMS), which communicates wirelessly exclusively with a Medtronic insulin pump, was assessed in 2 separate studies. METHODS: In the laboratory study (N=100), subject capillary fingertip samples were tested in duplicate using 3 test strip lots; accuracy was assessed based on ISO 15197:2013 section 6.3 accuracy criteria (95% within ±15mg/dl or ±15% of reference for glucose <100 and ≥100mg/dl, respectively). In the clinical trial (N=219), untrained subjects with diabetes tested capillary fingertip and palm blood samples and completed an ease-of-use questionnaire. BGMS and YSI glucose analyzer results were compared based on ISO 15197:2013 section 8 accuracy criteria. RESULTS: In the laboratory study, 100% of results met ISO 15197:2013 section 6.3 accuracy criteria. In the clinical trial, 98.6% of capillary fingertip and 97.2% of palm results from subjects met ISO 15197:2013 section 8 accuracy criteria. By Parkes-Consensus Error Grid analysis, 100% of subject capillary fingertip results were within Zone A. Based on questionnaire results, the majority of subjects found the BGMS easy to use. CONCLUSIONS: The BGMS exceeds ISO 15197:2013 section 6.3 and section 8 accuracy criteria in the laboratory and in the hands of untrained users with diabetes.

Asunto(s)

RESUMEN

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.

Asunto(s)

RESUMEN

Hypoglycemia in infants is common, is difficult to recognize, and may lead to permanent neurologic impairment. Low glucose concentrations and high hematocrits in newborns pose significant analytic challenges for whole blood glucose meters. Three Bayer glucose monitoring systems were evaluated using 211 blood samples from 162 neonates (age range 5 hours to 29 days, median age 3 days). Hematocrit and whole blood glucose were determined in heparinized whole blood, and plasma glucose was determined using the Roche Cobas 6000. Accuracy was evaluated against plasma concentrations using ISO 15197:2013 and CLSI POCT 12-A3 criteria. Glucose imprecision on the Cobas system was 1.8-2.6% (CV) from 26-610 mg/dL. Imprecision across all meter systems was 2.8% (CV) at 130 mg/dL. Glucose concentrations, hematocrit, and total bilirubin ranged from 20-150 mg/dL, 18 -75%, and 0.5-19.6 mg/dL, respectively. Linear regression analysis of whole blood versus plasma for the 3 combined systems yielded an average slope of 1.06 and correlation coefficient greater than 0.980. Bias between the Contour and Cobas was not significantly correlated with hematocrit. Greater than 99% of meter results were within 15 mg/dL and 20% of plasma results at glucose concentrations ≤ 75 and > 75 mg/dL, respectively. Of meter results, 97% were within 12.5 mg/dL of plasma results at concentrations ≤ 100 mg/dL, while 96% of meter results were within 12.5% of plasma at concentrations > 100 mg/dL. The Bayer CONTOUR Blood Glucose Monitoring Systems exceed ISO 15197:2013 and CLSI criteria in neonatal blood samples.

Asunto(s)

RESUMEN

BACKGROUND: The accuracy of the Contour(®) Plus (Bayer HealthCare LLC, Diabetes Care, Whippany, NJ) blood glucose monitoring system (BGMS) was evaluated in two separate studies. MATERIALS AND METHODS: In the laboratory study, fingerstick samples from 100 subjects were tested in duplicate using three test strip lots and assessed per International Organization for Standardization (ISO) 15197:2003, Section 7 (≥95% of results within ±15 mg/dL or ±20% of the reference result for samples with glucose concentrations <75 and ≥75 mg/dL, respectively) and ISO 15197:2013, Section 6.3 (≥95% of results within ±15 mg/dL or ±15% of the reference result for samples with glucose concentrations <100 and ≥100 mg/dL, respectively) accuracy criteria. In the clinical trial, 220 subjects with diabetes, naive to the BGMS, tested capillary glucose from fingertip and palm blood samples and completed an ease-of-use questionnaire. BGMS and YSI glucose analyzer results were compared. RESULTS: In the laboratory study, 100% of results met ISO 15197:2003 and ISO 15197:2013 accuracy criteria. In the clinical trial, 100% and 99.1% of subject fingerstick results and 98.1% and 96.7% of subject palm results met ISO 15197:2003 and ISO 15197:2013 accuracy criteria, respectively. By Parkes Consensus Error Grid analysis, 100% of subject fingerstick results and 98.1% of subject palm results were within Zone A (remainder within Zone B). Questionnaire results showed most subjects found the BGMS easy to use. CONCLUSIONS: The Contour Plus BGMS meets ISO 15197:2003 and ISO 15197:2013 accuracy criteria in the laboratory and when used by untrained individuals.

Asunto(s)

RESUMEN

OBJECTIVE: To assess differences between estimated blood glucose values and those measured on a blood glucose meter and the impact on self-care behavior in type 2 diabetes. RESEARCH DESIGN AND METHODS: Subjects ≥18 years with type 2 diabetes (N = 297) attending a Taking Control of Your Diabetes conference were asked questions about diabetes management and to estimate their current blood glucose. Study staff tested subjects' blood glucose on a meter. After seeing the result, subjects were again asked questions on diabetes management. CLINICAL TRIAL REGISTRATION: NCT01453413. MAIN OUTCOME MEASURE: The percentage of subject blood glucose estimations that were outside ISO 15197:2003 accuracy criteria (>±15 mg/dL or >±20% of meter glucose values). RESULTS: Nearly half (46%) of subjects estimated blood glucose values outside ISO 15197:2003 accuracy criteria. Time since last blood glucose test, time since last meal, testing frequency, and A1C did not have an effect on differences between estimated blood glucose values and meter results. In the questionnaire before blood glucose testing, most subjects strongly agreed, agreed, or neither agreed nor disagreed that 'I make decisions about my diabetes, such as my food intake or my insulin dose even when I do not test my blood sugar' (71%) and 'My body tells me without testing if my blood sugar is low or high' (77%). After blood glucose testing, 99% of subjects strongly agreed, agreed, or neither agreed nor disagreed that 'Knowing my blood sugar by checking could help me make different diabetes decisions'. CONCLUSIONS: Self-monitoring of blood glucose is an important component of diabetes self-management. Testing rather than guessing blood glucose values is important to obtain accurate results and inform people with type 2 diabetes to make effective, appropriate diabetes management decisions. A potential limitation of this study is that the subject population may not be representative of the general population of people with diabetes; however, the conference setting may attract a more motivated population, which could underestimate the magnitude of the results.

Asunto(s)