Performance of a new interference-resistant glucose meter

doi:10.1016/j.clinbiochem.2009.09.010

Clinical Biochemistry

Volume 43, Issues 1–2, January 2010, Pages 186-192

https://doi.org/10.1016/j.clinbiochem.2009.09.010 Get rights and content

Abstract

Objectives

Glucose meters are widely used in self and hospital monitoring of blood glucose. We examined the analytical performance of a StatStrip glucose monitoring system.

Design and methods

Linearity, % recovery and within-run imprecision were studied using glucose-spiked whole blood. A total of 120 heparinized samples were used in method comparison using a plasma hexokinase on the Dimension RxL MAX analyzer as the comparison method. Common interferences were tested on the StatStrip, Accu-Chek Advantage and the MediSense Optium glucose meters at low, middle and high glucose levels.

Results

The StatStrip assay showed excellent linearity and recovery. The coefficient of variations for imprecision were < 5%. This meter correlated well with the comparison method (y = 0.994X + 0.03; r = 0.995, S_y/x= 0.05 mmol/L, bias = − 0.01 mmol/L). Of the three meters tested, only the StatStrip showed interference < 10% for all spiked levels of acetaminophen, ascorbic acid, maltose and hematocrit at three levels of glucose tested.

Conclusions

The StatStrip meter showed good performance and is suitable for point-of-care hospital glucose testing.

Introduction

It is well established that diabetes mellitus (DM) and diabetes-related complications are a major health concern worldwide. The American Diabetes Association (ADA) clinical practice guidelines recommend that self-monitoring of blood glucose (SMBG) is important in the management of type 1 and type 2 diabetes to decrease the risk of complications [1], [2]. In recent years the value of glucose meters in point-of-care testing (POCT) by medical professionals and SMBG by patients have been widely accepted. These modern devices are commercially available, easy to use, allow rapid turnaround times and quantify measurements in very small volumes of specimen [3], [4]. Meters can provide a whole blood glucose measurement based on glucose oxidase or glucose dehydrogenase methods and measure either amperometric changes based on the oxidation or dehydrogenation of glucose, or colorimetric changes by linking the product of the enzymatic reaction to a chromophore. The methodologies used and the specifications of these meters have been reviewed and discussed [5], [6], [7], [8].

Since glucose meters are important tools in SMBG, it is recommended that the meters be accurate, precise and reliable. Different analytical goals have been suggested for the performance of glucose meters. The current ADA recommendation is for a total error of < 5% at glucose concentrations of 1.7-22.2 mmol/L [9]. The new Clinical and Laboratory Standards Institute (CLSI) guideline states that the results from the POC glucose monitoring system should agree within ± 0.8 mmol/L of the laboratory analyzer values at glucose concentrations below 4.2 mmol/L and within ± 20 % of the laboratory analyzer value at glucose concentrations at or above 4.2 mmol/L [10]. Kost et al. [11] have proposed a modification of the previous CLSI guideline that the discrepancy between meters and routine laboratory analyzers should not exceed + 0.8 mmol/L for glucose values < 5.6 mmol/L and + 15% for glucose values > 5.6 mmol/L, and have suggested that 95% of the individual results should fall within these limits. According to International Organization for Standardization (ISO) 15197:2003, 95% of the individual glucose results must be within ± 0.8 mmol/L of the comparison-method results at glucose concentrations below 4.20 mmol/L and within ± 20% of the comparison-method results for glucose concentrations at or above 4.20 mmol/L [12]. Clarke Error Grid analysis can also be used to evaluate glucose meter performance [13]. The Food and Drug Administration (FDA) requires all meters to have an error of < 20% at blood glucose concentrations between 1.7-22.2 mmol/L [14]. The analytical performances of most glucose meters presently available have been extensively evaluated. Several authors have reported good correlation between various meters and routine laboratory analyzers [15], [16], [17], [18]. Our aims in this study were to evaluate the analytical performance of the Nova StatStrip glucose meter and to compare the results to a routine laboratory method. The effects of acetaminophen, ascorbic acid, maltose and hematocrit on three glucose strip technologies were also assessed.

Section snippets

Equipment

The following blood glucose meters were used in the study: the Nova StatStrip glucose meter (Nova Biomedical, Waltham, MA, USA), the Roche Accu-Chek Advantage (Roche Diagnostics, Indianapolis, IN, USA), and the MediSense Optium (Abbott Diagnostics, Abbott Park, IL, USA). The Nova StatStrip glucose meter uses a modified glucose oxidase (MGO) based amperometric test system with hematocrit and other interference correction, while the Roche Accu-Chek Advantage and the Abbott Optium use glucose

Linearity and recovery study

Linearity of the Nova StatStrip glucose meter was determined using spiked whole blood specimens. The meter showed good linearity of response within the range of 1.5–33.3 mmol/L. The calculated linear regression equation was: y = 1.003x + 0.07, r = 1.000 (Fig. 1). The means of the percent recovery at low, middle and high glucose concentrations for the StatStrip, Accu-Chek and Optium were as follows: 98.8%, 101.9%, and 98.8%; 112.5%, 82.6%, and 74.7%; 66.7%, 70.4%, and 75.8%, respectively. Only the

Discussion

Self-monitoring of blood glucose using portable glucose meters is important in diabetes control [1]. Major problems for these devices are bias, interference by hematocrit and various blood constituents, and very high protein concentrations. Agreement with the routine method in the central laboratory is particularly important if different glucose meters are used. The reliability of glucose meters has recently been improved and several studies have evaluated the use of blood glucose meters and

Acknowledgments

The authors thank the Nova Biomedical Corporation for supplying the StatStrip Blood Glucose Monitoring system.

References (40)

SoldinS.J. et al.
Evaluation of the Abbott PCx-point of care glucose analyzer in a pediatric hospital
Clin. Biochem.
(2000)
Ken-Shwo Dai et al.
Accuracy of the EasyTouch blood glucose self-monitoring system: a study of 516 cases
Clin. Chim. Acta.
(2004)
Moatti-SiratD. et al.
Evaluating in vitro and in vivo the interference of ascorbate and acetaminophen on glucose detection by a needletype glucose sensor
Biosens. Bioelectron.
(1992)
American Diabetes Association Position Statement Tests of Glycemia of in Diabetes
Diabetes Care
(2004)
SacksD.B. et al.
Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus
Clin. Chem.
(2002)
WinkelmanJ.W. et al.
The fiscal consequences of central vs distributed testing of glucose
Clin. Chem.
(1994)
AlexC.P. et al.
Clinical utility of a bedside blood analyzer for measuring blood chemistry values in neonates
J. Perinatol.
(1998)
Titus K. Bedside glucose testing systems. CAP Today...
American Diabetes Association. Resource guide 2005. Blood glucose meters and data management system. Diabetes Forecast...
FordA.
Bedside glucose testing systems
CAP Today
(2006)

SlussP.M.

Bedside blood glucose testing systems: current technology

Point Care

(2006)

American Diabetes Association

Self-monitoring of diabetes

Diabetes Care

(1996)

Point-of-Care Blood-Glucose Testing in Acute and Chronic Care Facilities; Approved Guideline

(2002)

KostG.J. et al.

Multicenter study of oxygen insensitive handheld glucose point-of-care testing in critical care/hospital/ambulatory patients in the United States and Canada

Crit. Care Med.

(1998)

Sinternational Organization for Standardization

In vitro Diagnostic test systems—requirements for blood glucose monitoring systems for self-testing in managing diabetes mellitus. ISO 15197:2003 (E)

(2003)

ClarkeW.L. et al.

Evaluating clinical accuracy of systems for self-monitoring of blood glucose

Diabetes Care

(1987)

BriggsA.L. et al.

Self-monitoring blood glucose (SMBG): now and the future

J. Pharm. Pract.

(2004)

KilpatrickE.S. et al.

Variations in sample pH and pO2 affect ExacTech meter glucose measurements

Diabet. Med.

(1994)

KostG.J. et al.

Multicentre study of oxygen-insensitive handheld glucose point-of-care testing in critical care/hospital/ambulatory patients in the United States and Canada

Crit. Care Med.

(1998)

ChanceJ.J. et al.

Technical evaluation of five glucose meters with data management capabilities

Am. J. Clin. Pathol.

(1999)

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Determination of lactose in milk and milk-derived ingredients using biosensor-based techniques
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Lactose is the primary solid constituent of bovine milk, accounting for 35% of the total solids in whole milk, and is the primary constituent of many dairy ingredients, such as whole milk powder (about 40% dry-basis lactose) or whey powder (about 70% dry-basis lactose). As a result, the properties of several dairy products, particularly concentrated and dehydrated products, are dominated by lactose properties such as solubility, crystallization behavior, mutarotation properties, and tendency to Maillard browning. Lactose assays commonly employed by the dairy industry are time-consuming and require sophisticated equipment or trained staff to perform. A blood glucose meter (BGM) biosensor can be applied as an approach for measuring lactose in milk and milk products, where after hydrolysis of lactose into glucose and galactose, the resulting glucose content can be measured with the BGM. For correlating the glucose reading with the lactose content in milk and milk products, a calibration curve must be developed between the known lactose concentration and BGM reading. The BGM method can be a promising tool for rapid, low-cost analysis of lactose in milk and milk products for purposes such as quality control, process development, or ingredient standardization. However, the type of milk and milk product, amount of lactose present, pH of medium, and amount and type of nonlactose interferents must be taken into consideration during standardization of BGM usage for lactose estimation.
Technical note: Glucose concentration in dairy cows measured using 6 handheld meters designed for human use
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All handheld glucose meters evaluated in the present study were designed for human use and intended as monitoring tools for diabetic patients. In human blood specimens, hematocrit interferes with glucose concentration readings (Vanavanan et al., 2010). However, the hematocrit of cows is lower than that of humans; therefore, evaluating glucose concentration with handheld meters designed for humans may result in an overestimation of glucose concentration (Vanavanan et al., 2010).
The objective was to evaluate the precision and accuracy of 6 handheld glucose meters, designed for human use [Accu-Chek Aviva Plus (AC), Roche Diabetes Care, Mannheim, Germany; Aga Matrix (AM), AgaMatrix Inc., Salem, NH; Contour Next (CT), Bayer HealthCare LLC, Leverkusen, Germany; FreeStyle Precision Neo (FS), Abbott Diabetes Care Ltd., Alameda, CA; Nova Max Plus (NM), Nova Biomedical Corporation, Waltham, MA; and Precision Xtra (PX), Abbott Diabetes Care Ltd., Witney, UK] to measure blood glucose concentration in dairy cows. Blood samples from Jersey and Jersey × Holstein crossbreed cows (n = 97 for all; except CT, n = 71) were collected and analyzed in triplicate using the 6 handheld glucose meters evaluated. Plasma glucose was also measured with the laboratory reference method (hexokinase glucose-6-phosphate dehydrogenase). Based on the intra-assay coefficient of variation (CV), precision varied across handheld glucose meters: AC (2.2%), CT (4.0%), PX (4.7%), FS (5.6%), AM (6.2%), and NM (6.7%). Lin's concordance correlation coefficients between handheld glucose meters and the reference method were 0.75 for FS, 0.74 for PX, 0.62 for AC, 0.55 for CT, 0.53 for NM, and 0.48 for AM. Based on Passing-Bablok regression, the AM and PX meters showed bias in the measurements of blood glucose. Bland-Altman plots indicated a negative bias (FS = −0.25 mmol/L; CT = −0.60 mmol/L) or a positive bias (AM = 0.29 mmol/L; PX = 0.33 mmol/L; NM = 0.52 mmol/L; AC = 0.65 mmol/L) between handheld glucose meters and the reference method. All handheld glucose meters evaluated had wide limits of agreement (LoA) ranging from −0.18 to 1.47 mmol/L (AC, narrowest LoA) to −1.25 to 1.82 mmol/L (AM, widest LoA). Bias was the major contributor to the total observed error (TE_obs), accounting for 81.5% of the TE_obs in AC, 72.0% in CT, 64.9% in AM, 61.1% in NM, 57.8% in PX, and 56.2% in FS. Overall, although some handheld meters (AC, CT, and PX) showed satisfactory precision, none were accurate measuring glucose. Future studies should evaluate whether incorporating algorithms designed for cattle can improve accuracy and precision of handheld glucose meters.
Clinical impact of improved point-of-care glucose monitoring in neonatal intensive care using Nova StatStrip: Evidence for improved accuracy, better sensitivity, and reduced test utilization
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It uses multi-well technology in combination with a modified glucose oxidase amperometric test system to autocorrect for hematocrit and background noise [11]. We and others have demonstrated its improved analytical performance, in particular, resistance to hematocrit interferences, excellent accuracy against laboratory plasma measurements, and excellent precision < 4% coefficient of variation (CV) [10–14]. However, these studies have focused primarily on blood sampling across the normal range of glucose homeostasis and were performed mostly by trained laboratory operators.
Studies have demonstrated improved analytical performance of the Nova StatStrip glucose meter, but limited data is available on its clinical performance in critically ill neonates in the neonatal intensive care unit (NICU).
A retrospective charge review was conducted on 651 neonates admitted to the NICU over 2 years. Demographics, sample collection information, and clinical details were recorded. Glucose measurements were performed at the bedside using either the Nova StraStrip or LifeScan SureStep Flexx meters as well as corresponding measurements of laboratory venous plasma glucose. Performance was analyzed by receiver operator characteristic (ROC) curves for detecting hypoglycemia and critical glucose levels.
Linear regression analysis comparing StatStrip and laboratory venous plasma glucose samples demonstrated significantly tighter agreement (r² = 0.7994) and accuracy (mean bias = 0.13 mmol/L) than SureStep (r² = 0.6845 and mean bias = 0.53 mmol/L). StatStrip also showed improved sensitivity for detecting critical low glucose values ≤ 3.0 mmol/L (80.9 vs 68.9%, p < 0.05). ROC curve analysis further demonstrated excellent performance of StatStrip at this cutoff with an AUC of 0.98. Overall, neonates were also tested significantly less frequently with the StatStrip meter by 24% compared to SureStep.
Implementation of StatStrip led to better agreement with venous plasma glucose, improved detection of critical low glucose results, and more efficient test utilization. This study demonstrates the importance of accurate and sensitive glucose monitoring in the NICU.
Feasibility of continuous glucose monitoring in critically Ill emergency department patients
2012, Journal of Emergency Medicine
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In this study, we used a StatStrip® Xpress™ glucose monitor (Nova Biomedical) as capillary glucose measuring reference. The ability of this monitor to eliminate the aforementioned interferences has been validated in previous studies (17–19). This study has several limitations.
Glucose control is important in the management of critically ill patients. However, strict glucose control requires a large amount of nursing resources, especially in overcrowded emergency departments (EDs).
A continuous glucose monitoring system (CGMS) may be beneficial for glucose control in the ED. The objective of this study was to determine the test characteristics of CGMS in critically ill ED patients.
A prospective observational study of critically ill ED patients was conducted. During a patient’s visit to the ED, a CGMS sensor measured their interstitial fluid glucose levels continuously. Capillary glucose was measured every hour and used for glucose control and as a reference value. CGMS values were recorded in real time and compared with capillary glucose values.
A total of 122 pairs of capillary and CGMS glucose values in 12 patients were analyzed. The correlation coefficient was 0.87, and Bland-Altman analysis showed that 117 pairs (95.9%) were within a 95% confidence interval. A Clarke Error Grid Analysis indicated an overall accuracy of 96.8% (Zones A and B). However, the mean absolute relative difference (MARD) was significantly higher in the hypoglycemic range than in a normo- or hyperglycemic range (p = 0.001). The sensitivity and positive predictive value of CGMS for detecting hypoglycemia were 33.3% and 16.7%, respectively. The CGMS specificity and negative predictive value were 95.8% and 98.3%, respectively. There was no linear correlation between MARD and body mass index, axillary temperature, inotrope score, and base deficit (all p-value >0.05).
CGMS demonstrated good clinical accuracy by Clarke Error Grid Analysis. There also was high agreement between CGMS and capillary glucose levels. However, CGMS demonstrated only limited real-time hypoglycemia detection ability in critically ill ED patients.
Validation of a glucose meter at an intensive care unit
2012, Endocrinologia y Nutricion
Los pacientes ingresados en las unidades de cuidados intensivos (UCI) con hiperglucemia presentan mayor morbi-mortalidad que los pacientes normoglucémicos. Habitualmente, la monitorización de la glucemia de los pacientes en las unidades de cuidados intensivos es realizado por medio de glucómetros. El objetivo del estudio fue evaluar un glucómetro (StatStrip, Nova Biomedical) para determinar su grado de acuerdo con el método habitual de determinación de la glucemia en el laboratorio.
Se recogieron 89 muestras de diferentes pacientes (76,4% hombres y 23,6% mujeres) ingresados en una UCI durante los meses de septiembre a diciembre del 2010. En cada extracción, se recogió un tubo de heparina litio y otro tubo de EDTA. La alícuota de sangre total era utilizada para la determinación de glucemia mediante el glucómetro. El tubo de heparina litio era procesado a la misma vez para la determinación de la glucemia plasmática (Analizador Cobas 6000, Roche Diagnostic, SA). Para evaluar el grado de acuerdo entre los dos métodos, seguimos el procedimiento indicado en la guía EP-9-A2 del Clinical and Laboratory Standards Institute (CLSI).
La glucemia en sangre total medida por el glucómetro presentaba un valor medio de 126,53 ± 49,28 mg/dL con un rango de 33,5 a 431 mg/dL y la glucemia plasmática del método de laboratorio reflejaba un valor medio de 138,13 ± 78,6 mg/dL con un rango de 43-451 mg/dL. El coeficiente de correlación entre ambos métodos fue de 0,99 con un intervalo de confianza al 95% (IC) de 0,98 a 0,99; el coeficiente de determinación (R²) fue de 0,97 y el coeficiente de correlación intraclase fue 0,99 con un IC de 0,98 a 0,99.
El glucosímetro evaluado (StatStrip) presenta una buena asociación lineal, precisión y exactitud, cuando es comparado con el método de referencia del laboratorio clínico. Es un dispositivo adecuado para la monitorización de la glucosa.
Hyperglycemic patients admitted to Intensive care units (ICUs) have higher morbidity and mortality than normoglycemic patients. Blood glucose levels of ICU patients are usually measured with a glucose meter. The aim of this study was to evaluate a glucose meter (StatStrip, Nova Biomedical) to assess its agreement with the standard laboratory method for testing glucose.
Eighty-nine different samples were collected from patients (76.4% men and 23.6% women) admitted to an ICU from September to December 2010. Each blood sample was collected into two tubes, a lithium heparin tube and an EDTA tube. The total blood aliquot was used to measure glycemia using the glucose meter. The lithium heparin tube was processed at the same time for measuring plasma glucose (Cobas 6000 Analyzer, Roche Diagnostics, SA). Agreement between the two methods was assessed according to the EP-9-A2 Clinical Laboratory Standards Institute guideline.
Mean whole blood glucose level measured by the glucose meter was 126.53 + 49.28 mg/dL (range, 33.5-431 mg/dL), while mean plasma glucose value measured by the laboratory reference method was 138.13 + 78.6 mg/dL (range, 43-451 mg/dL). Correlation coefficient was 0.99, with a 95% confidence interval of 0.98 to 0.99. Coefficient of determination (R2) was 0.97, and intraclass correlation coefficient was 0.99 with a 95% CI of 0.98 to 0.99.
The tested glucose meter (StatStrip) shows a good linear association, precision, and accuracy when compared to the laboratory reference method. This device is adequate for glucose monitoring.
Glycemic control in the ICU
2011, Chest
Citation Excerpt :
In anemic patients, this correction results in POC devices reporting falsely high blood glucose concentrations,25,76 which may mean that hypoglycemia goes undetected, or inappropriate doses of insulin are administered. Some newer POC devices measure and correct for hematocrit77; thus, it is important that clinicians understand the characteristics of the particular POC device used in their own ICU. Blood glucose measurements using glucose oxidase systems are prone to errors caused by oxygen effects.
Hyperglycemia is common in critically ill patients, with approximately 90% of patients treated in an ICU developing blood glucose concentrations > 110 mg/dL (6.1 mmol/L). Landmark trials in Leuven, Belgium, suggested that targeting normoglycemia (a blood glucose concentration of 80-110 mg/dL [4.4-6.1 mmol/L]) reduced mortality and morbidity, but other investigators have not been able to replicate these findings. Recently, the international multicenter Normoglycemia in Intensive Care Evaluation-Survival Using Glucose Algorithm Regulation (NICE-SUGAR) study reported increased mortality with this approach, and recent meta-analyses do not support intensive glucose control for critically ill patients. Although the initial trials in Leuven produced enthusiasm and recommendations for intensive blood glucose control, the results of the NICE-SUGAR study have resulted in the more moderate recommendation to target a blood glucose concentration between 144 mg/dL and 180 mg/dL (8-10 mmol/L). As critical care practitioners pay greater attention to glycemic control, it has become clear that currently used point-of-care measuring systems are not accurate enough to target tight glucose control. Unresolved issues include whether increased blood glucose variability is inherently harmful and whether even moderate hypoglycemia can be tolerated in the quest for tighter blood glucose control. Future research must first address whether intensive glucose control can be delivered safely, and whether computerized decision support systems and newer technologies that allow accurate and continuous or near-continuous measurement of blood glucose can make this possible. Until such time, clinicians would be well advised to abide by the age-old adage to “first, do no harm.”

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Performance of a new interference-resistant glucose meter

Abstract

Objectives

Design and methods

Results

Conclusions

Introduction

Section snippets

Equipment

Linearity and recovery study

Discussion

Acknowledgments

Clin. Biochem.

Clin. Chim. Acta.

Biosens. Bioelectron.

Diabetes Care

Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus

Clin. Chem.

The fiscal consequences of central vs distributed testing of glucose

Clin. Chem.

Clinical utility of a bedside blood analyzer for measuring blood chemistry values in neonates

J. Perinatol.

Bedside glucose testing systems

CAP Today

Bedside blood glucose testing systems: current technology

Point Care

Self-monitoring of diabetes

Diabetes Care

Point-of-Care Blood-Glucose Testing in Acute and Chronic Care Facilities; Approved Guideline

Multicenter study of oxygen insensitive handheld glucose point-of-care testing in critical care/hospital/ambulatory patients in the United States and Canada

Crit. Care Med.

In vitro Diagnostic test systems—requirements for blood glucose monitoring systems for self-testing in managing diabetes mellitus. ISO 15197:2003 (E)

Evaluating clinical accuracy of systems for self-monitoring of blood glucose

Diabetes Care

Self-monitoring blood glucose (SMBG): now and the future

J. Pharm. Pract.

Variations in sample pH and pO2 affect ExacTech meter glucose measurements

Diabet. Med.

Multicentre study of oxygen-insensitive handheld glucose point-of-care testing in critical care/hospital/ambulatory patients in the United States and Canada

Crit. Care Med.

Technical evaluation of five glucose meters with data management capabilities

Am. J. Clin. Pathol.