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Sheen YJ, Wang JM, Tsai PF, Lee WJ, Hsu YC, Wang CY, Sheu WHH. Accuracy of Point-of-Care Blood Glucometers in Neonates and Critically Ill Adults. Clin Ther 2023; 45:643-648. [PMID: 37248091 DOI: 10.1016/j.clinthera.2023.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 05/01/2023] [Accepted: 05/06/2023] [Indexed: 05/31/2023]
Abstract
PURPOSE Inpatient glycemic management has become a common issue because of the increasing number of hospitalized patients with hyperglycemia. Point-of-care devices can enable timely inpatient glucose monitoring, which may lead to better outcomes. The accuracy of point-of-care testing in various clinical scenarios has been questioned, particularly in neonates and critically ill patients. This study aimed to evaluate the accuracy of the CONTOUR PLUS and CONTOUR PLUS ONE glucometers (new wireless systems that link to a smart mobile device) when used as point-of-care devices for blood glucose monitoring in neonates and critically ill adults in inpatient settings. METHODS This cross-sectional study was conducted at a medical center in central Taiwan and enrolled patients admitted to the neonatal intensive care unit, sick child room, or respiratory intensive care unit between November 2020 and April 2021. Neonates with suspected infection or abnormal blood coagulation and adults who had abnormal blood coagulation, were pregnant, had received organ transplants, or had undergone massive blood transfusions were excluded. The accuracy of the glucometers was determined based on the following criteria of the International Organization for Standardization (ISO) standard: 15197:2013. FINDINGS Overall, 114 neonates (mean age, 4.2 days [range, 0-28 days]; 65 boys [57.0%]) and 106 hospitalized critically ill adults (mean age, 68.2 years [range, 27-94 years]; 72 men [67.9%]) were enrolled in this study. The glucose values obtained with each glucometer had good precision, and all findings met the reference criteria of the within-lot results. All measurements of the neonates' venous blood by each glucometer met the accuracy criteria specified by ISO standard 15197:2013. Furthermore, 98.1% and 97.2% of the arterial blood glucose measurements for critically ill adults obtained with CONTOUR PLUS and CONTOUR PLUS ONE met the accuracy criteria, respectively. IMPLICATIONS Both glucose management systems met the accuracy criteria for venous blood from neonates and arterial blood from critically ill adults. Thus, the use of these 2 point-of-care devices in inpatient settings, including for neonates and critically ill adults, can be recommended to minimize limitations associated with the clinical application of point-of-care testing in glucose management. The wireless connection may play a role in the subsequent development of institution-wide virtual glycemic management under the supervision of a team of endocrinologists.
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Affiliation(s)
- Yi-Jing Sheen
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, Taiwan; School of Medicine, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan; Department of Post-Baccalaureate Medicine, College of Medicine, National Chung University.
| | - Jiunn-Min Wang
- Department of Pathology and Laboratory Medicine, Taichung Veterans General Hospital, Taiwan.
| | - Pi-Fen Tsai
- Department of Pathology and Laboratory Medicine, Taichung Veterans General Hospital, Taiwan.
| | - Wen-Jane Lee
- Department of Medical Research, Taichung Veterans General Hospital, Taiwan.
| | - Ya-Chi Hsu
- Division of Neonatology, Children's Medical Center, Taichung Veterans General Hospital, Taiwan; Department of Industrial Engineering and Enterprise Information, Tunghai University, Taichung, Taiwan.
| | - Chen-Yu Wang
- Department of Critical Care Medicine, Taichung Veterans General Hospital, Taiwan; Department of Nursing, Hung Kuang University, Taichung, Taiwan.
| | - Wayne H-H Sheu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, Taiwan; School of Medicine, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan; Division of Endocrinology and Metabolism, Department of Internal Medicine, Taipei Veterans General Hospital, Taiwan; School of Medicine, National Defense Medical Center, Taipei, Taiwan; Institute of Molecular and Genomic Medicine, National Health Research Institute, Zhu-Nan, Miaoli County, Taiwan.
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Elstub L, Nurse C, Grohowski L, Volgyesi P, Wolf D, Zelik K. Tibial bone forces can be monitored using shoe-worn wearable sensors during running. J Sports Sci 2022; 40:1741-1749. [PMID: 35938189 PMCID: PMC9938946 DOI: 10.1080/02640414.2022.2107816] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Tibial bone stress injury is a common overuse injury experienced by runners, which results from repetitive tissue forces. Wearable sensor systems (wearables) that monitor tibial forces could help understand and reduce injury incidence. However, there are currently no validated wearables that monitor tibial bone forces. Previous work using simulated wearables demonstrated accurate tibial force estimates by combining a shoe-worn inertial measurement unit (IMU) and pressure insole with a trained algorithm. This study aimed assessed how accurately tibial bone forces could be estimated with existing wearables. Nine recreational runners ran at a series of different speeds and slopes, and with various stride patterns. Shoe-worn IMU and insole data were input into a trained algorithm to estimate peak tibial force. We found an average error of 5.7% in peak tibial force estimates compared with lab-based estimates calculated using motion capture and a force instrumented treadmill. Insole calibration procedures were essential to achieving accurate tibial force estimates. We concluded that a shoe-worn, multi-sensor system is a promising approach to monitoring tibial bone forces in running. This study adds to the literature demonstrating the potential of wearables to monitor musculoskeletal forces, which could positively impact injury prevention, and scientific understanding.
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Affiliation(s)
- L.J Elstub
- Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee, United States
| | - C.A Nurse
- Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee, United States
| | - L.M Grohowski
- Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee, United States
| | - P. Volgyesi
- Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee, United States,Institute for Software Integrated Systems, Vanderbilt University, Nashville, Tennessee, United States
| | - D.N Wolf
- Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee, United States
| | - K.E. Zelik
- Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee, United States,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States,Department of Physical Medicine & Rehabilitation, Vanderbilt University, Nashville, Tennessee, United States
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Zhao Y, Zhang H, Li Y, Yu X, Cai Y, Sha X, Wang S, Zhan Z, Xu J, Liu L. AI powered electrochemical multi-component detection of insulin and glucose in serum. Biosens Bioelectron 2021; 186:113291. [PMID: 33971527 DOI: 10.1016/j.bios.2021.113291] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/09/2021] [Accepted: 04/27/2021] [Indexed: 12/27/2022]
Abstract
Multi-component detection of insulin and glucose in serum is of great importance and urgently needed in clinical diagnosis and treatment due to its economy and practicability. However, insulin and glucose can hardly be determined by traditional electrochemical detection methods. Their mixed oxidation currents and rare involvement in the reaction process make it difficult to decouple them. In this study, AI algorithms are introduced to power the electrochemical method to conquer this problem. First, the current curves of insulin, glucose, and their mixed solution are obtained using cyclic voltammetry. Then, seven features of the cyclic voltammetry curve are extracted as characteristic values for detecting the concentrations of insulin and glucose. Finally, after training using machine learning algorithms, insulin and glucose concentrations are decoupled and regressed accurately. The entire detection process only takes three minutes. It can detect insulin at the pmol level and glucose at the mmol level, which meets the basic clinical requirements. The average relative error in predicting insulin concentrations is around 6.515%, and that in predicting glucose concentrations is around 4.36%. To verify the performance and effectiveness of the proposed method, it is used to determine the concentrations of insulin and glucose in fetal bovine serum and real clinical serum samples. The results are satisfactory, demonstrating that the method can meet basic clinical needs. This multi-component testing system delivers acceptable detect limit and accuracy and has the merits of low cost and high efficiency, holding great potential for use in clinical diagnosis.
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Affiliation(s)
- Yuliang Zhao
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao, 066004, China
| | - Hongyu Zhang
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao, 066004, China.
| | - Yang Li
- School of Electrical Engineering, Yanshan University at Qinhuangdao, Qinhuangdao, 066004, China
| | - Xiaodong Yu
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao, 066004, China
| | - Yi Cai
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao, 066004, China
| | - Xiaopeng Sha
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao, 066004, China
| | - Shuyu Wang
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao, 066004, China
| | - Zhikun Zhan
- School of Electrical Engineering, Yanshan University at Qinhuangdao, Qinhuangdao, 066004, China.
| | - Jianghong Xu
- Qinhuangdao Hospital of Traditional Chinese Medicine, Qinhuangdao, 066004, China
| | - Lianqing Liu
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110000, China.
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Elder CT, Thigpin T, Karlnoski R, Smith D, Mozingo D, Carson JS. Results of a Multicenter Feasibility Study of an Automated Bedside Glucose Monitoring System in the Burn Intensive Care Setting. J Burn Care Res 2020; 41:535-538. [PMID: 31633750 DOI: 10.1093/jbcr/irz171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Intensive blood glucose regimens required for tight glycemic control in critically ill burn patients carry risk of hypoglycemia and are ultimately limited by the frequency of which serum glucose measurements can be feasibly monitored. Continuous inline glucose monitoring has the potential to significantly increase the frequency of serum glucose measurement. The objective of this study was to assess the accuracy of a continuous glucose monitor with inline capability (Optiscanner) in the burn intensive care setting. A multicenter, observational study was conducted at two academic burn centers. One hundred and six paired blood samples were collected from 10 patients and measured on the Optiscanner and the Yellow Springs Instrument. Values were plotted on a Clarke Error Grid and mean absolute relative difference calculated. Treatment was guided by existing hospital protocols using separately obtained values. 97.2% of results obtained from Optiscanner were within 25% of corresponding Yellow Springs Instrument values and 100% were within 30%. Mean absolute relative difference was calculated at 9.6%. Our findings suggest that a continuous glucose monitor with inline capability provides accurate blood glucose measurements among critically ill burn patients.
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Affiliation(s)
- Craig T Elder
- Department of Surgery, University of Florida, Gainesville
| | - Tera Thigpin
- Department of Surgery, University of Florida, Gainesville
| | - Rachel Karlnoski
- Direction, Clinical Operations, USF Morsani College of Medicine, Office of Clinical Research, Tampa, Florida
| | - David Smith
- College of Medicine Plastic Surgery, Department of Plastic Surgery and Tampa General Hospital Burn Center, University of South Florida
| | - David Mozingo
- Division of Acute Care Surgery and Burns, UF Shands Burn Center, Department of Surgery, University of Florida, Gainesville
| | - Joshua S Carson
- Division of Acute Care Surgery and Burns, UF Shands Burn Center, Department of Surgery, University of Florida, Gainesville
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Cho MJ, Bunsawat K, Kim HJ, Yoon ES, Jae SY. The acute effects of interrupting prolonged sitting with stair climbing on vascular and metabolic function after a high-fat meal. Eur J Appl Physiol 2020; 120:829-839. [DOI: 10.1007/s00421-020-04321-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 02/09/2020] [Indexed: 01/02/2023]
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Abstract
The aim of this study was to assess the accuracy of blood glucose monitors (BGMs) from studies reported in the medical literature. A literature review was performed of publications between 2010 and 2017 that presented data about the accuracy of BGMs using ISO 15197 2003 and/or ISO 15197 2013 as target standards. We found 58 publications describing the performance of 143 unique BGM systems, 59 of which were Food and Drug Administration (FDA) cleared. When compared with non-FDA-cleared BGMs, FDA-cleared BGMs were significantly more likely to pass both ISO 15197 2003 (OR = 2.39, CI 1.45-3.92, P < 0.01) and ISO 15197 2013 standards (OR = 2.20, CI 1.51-3.27, P < 0.01). Newer meters were more likely to pass both ISO 15197 2003 and ISO 15197 2013 standards. Many of the studies were supported by BGM manufacturers, and when compared with independent studies, an FDA-cleared BGM was significantly more likely to pass in a manufacturer-supported study for both ISO 15197 2003 (OR = 22.4, CI 8.73-21.57, P < 0.001) and ISO 15197 2013 (OR = 23.08, CI 10.16-60.03, P < 0.001). BGM accuracy should be assessed independently following regulatory clearance to ensure accurate performance. Failure to meet performance levels mandated by standards can result in deleterious clinical and economic effects.
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Affiliation(s)
- Fraya King
- 1 Diabetes Research Institute, Mills-Peninsula Medical Center , San Mateo, California
| | - David Ahn
- 2 Department of Endocrinology, University of California , Los Angeles, Valencia, California
| | - Victoria Hsiao
- 3 Department of Medicine, University of California, San Francisco , San Francisco, California
| | - Travis Porco
- 4 FI Proctor Foundation for Research in Ophthalmology and Department of Ophthalmology, University of California , San Francisco, San Francisco, California
| | - David C Klonoff
- 1 Diabetes Research Institute, Mills-Peninsula Medical Center , San Mateo, California
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Yu-Fei W, Wei-Ping J, Ming-Hsun W, Miao-O C, Ming-Chang H, Chi-Pin W, Ming-Shih L. Accuracy Evaluation of 19 Blood Glucose Monitoring Systems Manufactured in the Asia-Pacific Region: A Multicenter Study. J Diabetes Sci Technol 2017; 11:953-965. [PMID: 28480733 PMCID: PMC5950995 DOI: 10.1177/1932296817705143] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND System accuracy of current blood glucose monitors (BGMs) in the market has already been evaluated extensively, yet mostly focused on European and North American manufacturers. Data on BGMs manufactured in the Asia-Pacific region remain to be established. In this study, we sought to assess the accuracy performance of 19 BGMs manufactured in the Asia-pacific region. METHODS A total of 19 BGMs were obtained from local pharmacies in China. The study was conducted at three hospitals located in the Asia-Pacific region. Measurement results of each system were compared with results of the reference instrument (YSI 2300 PLUS Glucose Analyzer), and accuracy evaluation was performed in accordance to the ISO 15197:2003 and updated 2015 guidelines. Radar plots, which is a new method, are described herein to visualize the analytical performance of the 19 BGMs evaluated. Consensus error grid is a tool for evaluating the clinical significance of the results. RESULTS The 19 BGMs resulted in a satisfaction rate between 83.5% and 100.0% within ISO 15197:2003 error limits, and between 71.3% and 100.0% within EN ISO 15197:2015 (ISO 15197:2013) error limits. CONCLUSIONS Of the 19 BGMs evaluated, 12 met the minimal accuracy requirement of the ISO 15197:2003 standard, whereas only 4 met the tighter EN ISO 15197:2015 (ISO 15197:2013) requirements. Accuracy evaluation of BGMs should be performed regularly to maximize patient safety.
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Affiliation(s)
- Wang Yu-Fei
- Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
- Shanghai Clinical Medical Center of Diabetes, Shanghai, China
- Shanghai Key Clinical Center of Metabolic Disease, Shanghai, China
- Shanghai Institute for Diabetes, Shanghai, China
- Shanghai Key Laboratory of Diabetes, Shanghai, China
- Diabetes Research Laboratory, Shanghai Jiao Tong University Affiliated First People’s Hospital, Shanghai, China
| | - Jia Wei-Ping
- Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | | | | | - Hsieh Ming-Chang
- Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan
- School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Wang Chi-Pin
- Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan
- School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Lee Ming-Shih
- Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan
- School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
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8
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Zhang R, Gao F, Feng X, Liu S, Kishor R, Luo Y, Zheng Y. Noninvasive photoacoustic measurement of glucose by data fusion. Analyst 2017; 142:2892-2896. [DOI: 10.1039/c7an00743d] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A novel method of noninvasive photoacoustic glucose measurement utilizing the amplitude and phase difference information.
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Affiliation(s)
- Ruochong Zhang
- School of Electrical and Electronic Engineering
- Nanyang Technological University
- 639798 Singapore
| | - Fei Gao
- School of Electrical and Electronic Engineering
- Nanyang Technological University
- 639798 Singapore
- School of Information Science and Technology
- ShanghaiTech University
| | - Xiaohua Feng
- School of Electrical and Electronic Engineering
- Nanyang Technological University
- 639798 Singapore
| | - Siyu Liu
- School of Electrical and Electronic Engineering
- Nanyang Technological University
- 639798 Singapore
| | - Rahul Kishor
- School of Electrical and Electronic Engineering
- Nanyang Technological University
- 639798 Singapore
| | - Yunqi Luo
- School of Electrical and Electronic Engineering
- Nanyang Technological University
- 639798 Singapore
| | - Yuanjin Zheng
- School of Electrical and Electronic Engineering
- Nanyang Technological University
- 639798 Singapore
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9
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Bailey SL, Ayles H, Beyers N, Godfrey-Faussett P, Muyoyeta M, du Toit E, Yudkin JS, Floyd S. The association of hyperglycaemia with prevalent tuberculosis: a population-based cross-sectional study. BMC Infect Dis 2016; 16:733. [PMID: 27919230 PMCID: PMC5139015 DOI: 10.1186/s12879-016-2066-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 11/25/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Systematic reviews suggest that the incidence of diagnosed tuberculosis is two- to- three times higher in those with diabetes mellitus than in those without. Few studies have previously reported the association between diabetes or hyperglycaemia and the prevalence of active tuberculosis and none in a population-based study with microbiologically-defined tuberculosis. Most have instead concentrated on cases of diagnosed tuberculosis that present to health facilities. We had the opportunity to measure glycaemia alongside prevalent tuberculosis. A focus on prevalent tuberculosis enables estimation of the contribution of hyperglycaemia to the population prevalence of tuberculosis. METHODS A population-based cross-sectional study was conducted among adults in 24 communities from Zambia and the Western Cape (WC) province of South Africa. Prevalent tuberculosis was defined by the presence of a respiratory sample that was culture positive for M. tuberculosis. Glycaemia was measured by random blood glucose (RBG) concentration. Association with prevalent tuberculosis was explored across the whole spectrum of glycaemia. RESULTS Among 27,800 Zambian and 11,367 Western Cape participants, 4,431 (15.9%) and 1,835 (16.1%) respectively had a RBG concentration ≥7.0 mmol/L, and 405 (1.5%) and 322 (2.8%) respectively had a RBG concentration ≥11.1 mmol/L. In Zambia, the prevalence of tuberculosis was 0 · 5% (142/27,395) among individuals with RBG concentration <11.1 mmol/L and also ≥11.1 mmol/L (2/405); corresponding figures for WC were 2 · 5% (272/11,045) and 4 · 0% (13/322). There was evidence for a positive linear association between hyperglycaemia and pulmonary prevalent tuberculosis. Taking a RBG cut-off 11.1 mmol/L, a combined analysis of data from Zambian and WC communities found evidence of association between hyperglycaemia and TB (adjusted odds ratio = 2 · 15, 95% CI [1 · 17-3 · 94]). The population attributable fraction of prevalent tuberculosis to hyperglycaemia for Zambia and WC combined was 0.99% (95% CI 0 · 12%-1.85%) for hyperglycaemia with a RBG cut-off of 11.1 mmol/L. CONCLUSIONS This study demonstrates an association between hyperglycaemia and prevalent tuberculosis in a large population-based survey in Zambia and Western Cape. However, assuming causation, this association contributes little to the prevalence of TB in these populations.
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Affiliation(s)
- Sarah Lou Bailey
- LSHTM TB Centre and Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK. .,ZAMBART Project, Lusaka, Zambia.
| | - Helen Ayles
- LSHTM TB Centre and Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK.,ZAMBART Project, Lusaka, Zambia
| | - Nulda Beyers
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch, South Africa
| | - Peter Godfrey-Faussett
- LSHTM TB Centre and Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Elizabeth du Toit
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch, South Africa
| | | | - Sian Floyd
- LSHTM TB Centre and Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
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Pardo S, Simmons DA. The Quantitative Relationship Between ISO 15197 Accuracy Criteria and Mean Absolute Relative Difference (MARD) in the Evaluation of Analytical Performance of Self-Monitoring of Blood Glucose (SMBG) Systems. J Diabetes Sci Technol 2016; 10:1182-7. [PMID: 27118729 PMCID: PMC5032952 DOI: 10.1177/1932296816644468] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
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%.
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Naugler C, Zhang Z, Redman L. WITHDRAWN: Performance of Community Blood Glucose Meters in Calgary, Alberta: An Analysis of Quality Assurance Data. Can J Diabetes 2016; 40 Suppl 1:21-3. [DOI: 10.1016/j.jcjd.2016.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 04/16/2014] [Accepted: 04/20/2014] [Indexed: 11/29/2022]
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12
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Setford S, Smith A, McColl D, Grady M, Koria K, Cameron H. Evaluation of the performance of the OneTouch Select Plus blood glucose test system against ISO 15197:2013. Expert Rev Med Devices 2015; 12:771-81. [PMID: 26488139 DOI: 10.1586/17434440.2015.1102049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVES Assess laboratory and in-clinic performance of the OneTouch Select(®) Plus test system against ISO 15197:2013 standard for measurement of blood glucose. METHODS System performance assessed in laboratory against key patient, environmental and pharmacologic factors. User performance was assessed in clinic by system-naïve lay-users. Healthcare professionals assessed system accuracy on diabetes subjects in clinic. RESULTS The system demonstrated high levels of performance, meeting ISO 15197:2013 requirements in laboratory testing (precision, linearity, hematocrit, temperature, humidity and altitude). System performance was tested against 28 interferents, with an adverse interfering effect only being recorded for pralidoxime iodide. Clinic user performance results fulfilled ISO 15197:2013 accuracy criteria. Subjects agreed that the color range indicator clearly showed if they were low, in-range or high and helped them better understand glucose results. CONCLUSION The system evaluated is accurate and meets all ISO 15197:2013 requirements as per the tests described. The color range indicator helped subjects understand glucose results and supports patients in following healthcare professional recommendations on glucose targets.
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Affiliation(s)
| | | | | | - Mike Grady
- a LifeScan Scotland Ltd ., Inverness , UK
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13
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Freckmann G, Link M, Schmid C, Pleus S, Baumstark A, Haug C. System Accuracy Evaluation of Different Blood Glucose Monitoring Systems Following ISO 15197:2013 by Using Two Different Comparison Methods. Diabetes Technol Ther 2015; 17:635-48. [PMID: 26110670 DOI: 10.1089/dia.2015.0085] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Adherence to established standards (e.g., International Organization for Standardization [ISO] 15197) is important to ensure comparable and sufficient accuracy of systems for self-monitoring of blood glucose (SMBG). Accuracy evaluation was performed for different SMBG systems available in Europe with three reagent lots each. MATERIALS AND METHODS Test procedures followed the recently published revision ISO 15197:2013. Comparison measurements were performed with a glucose oxidase (YSI 2300 STAT Plus™ glucose analyzer; YSI Inc., Yellow Springs, OH) and a hexokinase (cobas Integra(®) 400 Plus analyzer; Roche Instrument Center, Rotkreuz, Switzerland) method. Compliance with ISO 15197:2013 accuracy criteria was determined by calculating the percentage of results within ±15% or within ±0.83 mmol/L of the comparison measurement results for glucose concentrations at and above or below 5.55 mmol/L, respectively, and by calculating the percentage of results within consensus error grid Zones A and B. RESULTS Seven systems showed with all three tested lots that 95-100% of the results were within the accuracy limits of ISO 15197:2013 and that 100% of results were within consensus error grid Zones A and B, irrespective of the comparison method used. Regarding results of individual lots, slight differences between the glucose oxidase method and the hexokinase method were found. Accuracy criteria of ISO 15197:2003 (±20% for concentrations ≥4.2 mmol/L and±0.83 mmol/L for concentrations <4.2 mmol/L) were fulfilled by eight systems with all three lots and by one system with two lots. CONCLUSIONS In this study, seven systems complied with the accuracy criteria of ISO 15197:2013. The results also indicate that the comparison measurement method/system is important, as it may have a considerable impact on accuracy data obtained for a system.
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Affiliation(s)
- Guido Freckmann
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH , Ulm, Germany
| | - Manuela Link
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH , Ulm, Germany
| | - Christina Schmid
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH , Ulm, Germany
| | - Stefan Pleus
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH , Ulm, Germany
| | - Annette Baumstark
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH , Ulm, Germany
| | - Cornelia Haug
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH , Ulm, Germany
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14
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Freckmann G, Schmid C, Baumstark A, Rutschmann M, Haug C, Heinemann L. Analytical Performance Requirements for Systems for Self-Monitoring of Blood Glucose With Focus on System Accuracy: Relevant Differences Among ISO 15197:2003, ISO 15197:2013, and Current FDA Recommendations. J Diabetes Sci Technol 2015; 9:885-94. [PMID: 25872965 PMCID: PMC4525642 DOI: 10.1177/1932296815580160] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In the European Union (EU), the ISO (International Organization for Standardization) 15197 standard is applicable for the evaluation of systems for self-monitoring of blood glucose (SMBG) before the market approval. In 2013, a revised version of this standard was published. Relevant revisions in the analytical performance requirements are the inclusion of the evaluation of influence quantities, for example, hematocrit, and some changes in the testing procedures for measurement precision and system accuracy evaluation, for example, number of test strip lots. Regarding system accuracy evaluation, the most important change is the inclusion of more stringent accuracy criteria. In 2014, the Food and Drug Administration (FDA) in the United States published their own guidance document for the premarket evaluation of SMBG systems with even more stringent system accuracy criteria than stipulated by ISO 15197:2013. The establishment of strict accuracy criteria applicable for the premarket evaluation is a possible approach to further improve the measurement quality of SMBG systems. However, the system accuracy testing procedure is quite complex, and some critical aspects, for example, systematic measurement difference between the reference measurement procedure and a higher-order procedure, may potentially limit the apparent accuracy of a given system. Therefore, the implementation of a harmonized reference measurement procedure for which traceability to standards of higher order is verified through an unbroken, documented chain of calibrations is desirable. In addition, the establishment of regular and standardized post-marketing evaluations of distributed test strip lots should be considered as an approach toward an improved measurement quality of available SMBG systems.
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Affiliation(s)
- Guido Freckmann
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH, Ulm, Germany
| | - Christina Schmid
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH, Ulm, Germany
| | - Annette Baumstark
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH, Ulm, Germany
| | | | - Cornelia Haug
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH, Ulm, Germany
| | - Lutz Heinemann
- Profil Institut für Stoffwechselforschung GmbH, Neuss, Germany
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15
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Bailey TS, Chang A, Christiansen M. Clinical accuracy of a continuous glucose monitoring system with an advanced algorithm. J Diabetes Sci Technol 2015; 9:209-14. [PMID: 25370149 PMCID: PMC4604574 DOI: 10.1177/1932296814559746] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We assessed the performance of a modified Dexcom G4 Platinum system with an advanced algorithm, in comparison with frequent venous samples measured on a laboratory reference (YSI) during a clinic session and in comparison to self-monitored blood glucose (SMBG) during home use. Fifty-one subjects with diabetes were enrolled in a prospective multicenter study. Subjects wore 1 sensor for 7-day use and participated in one 12-hour in-clinic session on day 1, 4, or 7 to collect YSI reference venous glucose every 15 minutes and capillary SMBG test every 30 minutes. Carbohydrate consumption and insulin dosing and timing were manipulated to obtain data in low and high glucose ranges. In comparison with the laboratory reference method (n = 2,263) the system provided a mean and median absolute relative differences (ARD) of 9.0% and 7.0%, respectively. The mean absolute difference for CGM was 6.4 mg/dL when the YSIs were within hypoglycemia ranges (≤ 70 mg/dL). The percentage in the clinically accurate Clarke error grid A zone was 92.4% and in the benign error B zone was 7.1%. Majority of the sensors (73%) had an aggregated MARD in reference to YSI ≤ 10%. The MARD of CGM-SMBG for home use was 11.3%. The study showed that the point and rate accuracy, clinical accuracy, reliability, and consistency over the duration of wear and across glycemic ranges were superior to current commercial real-time CGM systems. The performance of this CGM is reaching that of a self-monitoring blood glucose meter in real use environment.
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Affiliation(s)
| | - Anna Chang
- John Muir Physician Network Clinical Research Center, Concord, CA, USA
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16
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Moodley N, Ngxamngxa U, Turzyniecka MJ, Pillay TS. Historical perspectives in clinical pathology: a history of glucose measurement. J Clin Pathol 2015; 68:258-64. [PMID: 25568429 DOI: 10.1136/jclinpath-2014-202672] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
This is the second in the series of historical articles dealing with developments in clinical pathology. As one of the most commonly measured analytes in pathology, the assessment of glucose dates back to the time of the ancient Egyptians. It was only in the 19th century that advances in chemistry led to the identification of the sugar in urine being glucose. The following century witnessed the development of more chemical and enzymatic methods which became incorporated into the modern analysers and point-of-care instruments which are as ubiquitous as the modern day cellphones. Tracking the milestones in these developments shows the striking paradigms and the many parallels in the development of other clinical chemistry methods.
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Affiliation(s)
- Nareshni Moodley
- Department of Chemical Pathology & NHLS Inkosi Albert Luthuli Central Hospital, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Unathi Ngxamngxa
- Department of Chemical Pathology & NHLS Inkosi Albert Luthuli Central Hospital, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Magdalena J Turzyniecka
- Department of Chemical Pathology & NHLS Inkosi Albert Luthuli Central Hospital, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Tahir S Pillay
- Faculty of Health Sciences and Steve Biko Academic Hospital, Department of Chemical Pathology and NHLS Tshwane Academic Division, University of Pretoria, Pretoria, South Africa Division of Chemical Pathology, Department of Clinical Laboratory Sciences, University of Cape Town, Cape Town, South Africa
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17
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Cichosz SL, Frystyk J, Tarnow L, Fleischer J. Combining information of autonomic modulation and CGM measurements enables prediction and improves detection of spontaneous hypoglycemic events. J Diabetes Sci Technol 2015; 9:132-7. [PMID: 25216731 PMCID: PMC4495539 DOI: 10.1177/1932296814549830] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We have previously tested, in a laboratory setting, a novel algorithm that enables prediction of hypoglycemia. The algorithm integrates information of autonomic modulation, based on heart rate variability (HRV), and data based on a continuous glucose monitoring (CGM) device. Now, we investigate whether the algorithm is suitable for prediction of hypoglycemia and for improvement of hypoglycemic detection during normal daily activities. Twenty-one adults (13 men) with T1D prone to hypoglycemia were recruited and monitored with CGM and a Holter device while they performed normal daily activities. We used our developed algorithm (a pattern classification method) to predict spontaneous hypoglycemia based on CGM and HRV. We compared 3 different models; (i) a model containing raw data from the CGM device; (ii) a CGM* model containing data derived from the CGM device signal; and (iii) a CGM+HRV model-combining model (ii) with HRV data. A total of 12 hypoglycemic events (glucose levels < 3.9 mmol/L, 70 mg/dL) and 237 euglycemic measurements were included. For a 20-minute prediction, model (i) resulted in a ROC AUC of 0.69. If a high sensitivity of 100% was chosen, the corresponding specificity was 69%. (ii) The CGM* model yielded a ROC AUC of 0.92 with a corresponding sensitivity of 100% and specificity of 71%. (iii) The CGM+HRV model yielded a ROC AUC of 0.96 with a corresponding sensitivity of 100% and specificity of 91%. Data shows that adding information of autonomic modulation to CGM measurements enables prediction and improves the detection of hypoglycemia.
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Affiliation(s)
- Simon Lebech Cichosz
- Department of Endocrinology and Internal Medicine and Medical Research Laboratory, Aarhus University Hospital, Denmark Department of Health Science and Technology, Aalborg University, Denmark
| | - Jan Frystyk
- Department of Endocrinology and Internal Medicine and Medical Research Laboratory, Aarhus University Hospital, Denmark
| | - Lise Tarnow
- Steno Diabetes Center, Department of Clinical Epidemiology, Aarhus University and Nordsjaellands Hospitaler Hilleroed, Denmark
| | - Jesper Fleischer
- Department of Endocrinology and Internal Medicine and Medical Research Laboratory, Aarhus University Hospital, Denmark
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18
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Klaff LJ, Brazg R, Hughes K, Tideman AM, Schachner HC, Stenger P, Pardo S, Dunne N, Parkes JL. 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. Diabetes Technol Ther 2015; 17:8-15. [PMID: 25260047 DOI: 10.1089/dia.2014.0069] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
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.
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19
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System accuracy evaluation of the GlucoRx nexus voice TD-4280 blood glucose monitoring system. DISEASE MARKERS 2014; 2014:602586. [PMID: 25374434 PMCID: PMC4211321 DOI: 10.1155/2014/602586] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 09/15/2014] [Indexed: 12/19/2022]
Abstract
Use of blood glucose (BG) meters in the self-monitoring of blood glucose (SMBG) significantly lowers the risk of diabetic complications. With several BG meters now commercially available, the International Organization for Standardization (ISO) ensures that each BG meter conforms to a set degree of accuracy. Although adherence to ISO guidelines is a prerequisite for commercialization in Europe, several BG meters claim to meet the ISO guidelines yet fail to do so on internal validation. We conducted a study to determine whether the accuracy of the GlucoRx Nexus TD-4280 meter, utilized by our department for its cost-effectiveness, complied with ISO guidelines. 105 patients requiring laboratory blood glucose analysis were randomly selected and reference measurements were determined by the UniCel DxC 800 clinical system. Overall the BG meter failed to adhere to the ≥95% accuracy criterion required by both the 15197:2003 (overall accuracy 92.4%) and 15197:2013 protocol (overall accuracy 86.7%). Inaccurate meters have an inherent risk of over- and/or underestimating the true BG concentration, thereby risking patients to incorrect therapeutic interventions. Our study demonstrates the importance of internally validating the accuracy of BG meters to ensure that its accuracy is accepted by standardized guidelines.
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20
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Rajendran R, Rayman G. Point-of-care blood glucose testing for diabetes care in hospitalized patients: an evidence-based review. J Diabetes Sci Technol 2014; 8:1081-90. [PMID: 25355711 PMCID: PMC4455482 DOI: 10.1177/1932296814538940] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Glycemic control in hospitalized patients with diabetes requires accurate near-patient glucose monitoring systems. In the past decade, point-of-care blood glucose monitoring devices have become the mainstay of near-patient glucose monitoring in hospitals across the world. In this article, we focus on its history, accuracy, clinical use, and cost-effectiveness. Point-of-care devices have evolved from 1.2 kg instruments with no informatics to handheld lightweight portable devices with advanced connectivity features. Their accuracy however remains a subject of debate, and new standards for their approval have now been issued by both the International Organization for Standardization and the Clinical and Laboratory Standards Institute. While their cost-effectiveness remains to be proved, their clinical value for managing inpatients with diabetes remains unchallenged. This evidence-based review provides an overall view of its use in the hospital setting.
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21
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Naugler C, Zhang Z, Redman L. Performance of community blood glucose meters in calgary, alberta: an analysis of quality assurance data. Can J Diabetes 2014; 38:326-8. [PMID: 25168423 DOI: 10.1016/j.jcjd.2014.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 04/16/2014] [Accepted: 04/20/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVE The self-monitoring of blood glucose plays a critical role in management of diabetes mellitus. Although laboratory comparisons of glucose meter accuracy are often acceptable, clinical comparisons show frequent inaccuracies. In this paper, we evaluate the accuracy of self-monitoring blood glucose meters using glucose meter and serum comparisons from a large Canadian laboratory. METHODS This study was performed using secondary data obtained from the Laboratory Information System of Calgary Services, the sole provider of laboratory testing to Calgary and surrounding areas. We examined anonymous quality assurance data for glucose meter comparisons performed on home glucose meters between January 1, 2010, and April 30, 2013. RESULTS A total of 39 542 comparisons were recorded on 18 540 different subjects. Overall, 6.7% of differences were greater than the current International Standards Organization standard of 15%, and 3.7% exceeded the Canadian guideline of 20%. CONCLUSIONS Glucose meter checks were infrequently performed (on average, once per 1.6 years). A significant subset of meter results was inaccurate.
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Affiliation(s)
- Christopher Naugler
- University of Calgary and Calgary Laboratory Services, Calgary, Alberta, Canada.
| | - Ziyu Zhang
- University of Calgary and Calgary Laboratory Services, Calgary, Alberta, Canada
| | - Lyle Redman
- University of Calgary and Calgary Laboratory Services, Calgary, Alberta, Canada
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22
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Noble M, Rippeth J, Edington D, Rayman G, Brandon-Jones S, Hollowood Z, Kew S. Clinical evaluation of a novel on-strip calibration method for blood glucose measurement. J Diabetes Sci Technol 2014; 8:766-75. [PMID: 24876432 PMCID: PMC4764217 DOI: 10.1177/1932296814532575] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study evaluated a novel technology for improving accuracy of self-monitoring of blood glucose (SMBG). The technology calibrates each and every test by measuring the response from a predetermined amount of glucose present in the sample chamber of each test strip. SMBG test strips were modified to include a lid coated with a fast dissolving formulation containing glucose. These test strips were characterized for hematocrit (Hct) and temperature induced error response to develop a calibration algorithm. The modified test strips were used in a clinical evaluation involving fingerstick blood samples from 160 subjects. Experiments involving Hct and temperature induced errors show that the technology generates a signal characteristic of the error conditions in any particular test, but independent of glucose concentration, allowing a correction algorithm to be derived. The approach substantially reduced Hct and temperature derived errors. Clinical evaluation using fingerstick blood directly applied to prototype strips showed the error (measured as MARD) was reduced from 11.1 to 5.9% by the on-strip correction approach and the number of outliers reduced by approximately 90%. This technology could improve the accuracy and precision of glucose monitoring systems and so reduce decision errors particularly in clinical situations where hematocrit and temperature may be significant confounders.
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Affiliation(s)
- Michael Noble
- Exacsys Ltd, Cambridge Technology Centre, Melbourn, UK
| | - John Rippeth
- Exacsys Ltd, Cambridge Technology Centre, Melbourn, UK
| | | | - Gerry Rayman
- Ipswich Hospital NHS Trust, Diabetes Research Centre, Ipswich Hospital National Health Service Trust, Suffolk, UK
| | | | - Zoe Hollowood
- PA Consulting Group, Cambridge Technology Centre, Melbourn, UK
| | - Simon Kew
- PA Consulting Group, Cambridge Technology Centre, Melbourn, UK
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23
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Huang TY, Chang HW, Tsao MF, Chuang SM, Ni CC, Sue JW, Lin HC, Hsu CT. Evaluation of accuracy of FAD-GDH- and mutant Q-GDH-based blood glucose monitors in multi-patient populations. Clin Chim Acta 2014; 433:28-33. [PMID: 24613515 DOI: 10.1016/j.cca.2014.02.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 01/27/2014] [Accepted: 02/25/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND Glucose dehydrogenases have been highly promoted to high-accuracy blood glucose (BG) monitors. The flavin adenine dinucleotide glucose dehydrogenase (FAD-GDH) and mutant variant of quinoprotein glucose dehydrogenase (Mut. Q-GDH) are widely used in high-performance BG monitors for multi-patient use. Therefore we conducted accuracy evaluation of the GDH monitors, FAD-GDH-based GM700 and Mut. Q-GDH-based Performa. METHODS Different patients were enrolled: patients with and without diabetes, patients receiving respiratory therapies, hemodialysis (HD) and peritoneal dialysis (PD) patients, and neonates. The accuracy evaluation of FAD-GDH- and Mut. Q-GDH-based monitors referred to ISO 15197:2013 which applies new criteria for the minion accuracy requirements: more than 95% of the blood glucose readings shall fall within ±15mg/dL of the reference method at glucose concentration <100mg/dL and within ±15% of the reference method at glucose concentration ≥100mg/dL. Bland-Altman plots were used to evaluate the 2 GDH monitors as well. RESULTS Bland-Altman plots visualized excellent precision of the BG monitors. The 95% limit agreement of overall results for the FAD-GDH-based monitors was within ±12% and that for the Mut. Q-GDH-based monitors was from -10 to +17%. Both BG monitors met the accuracy requirements of ISO 15197:2013. The FAD-GDH-based monitor performed better with neonates and patients with and without diabetes, and the Mut. Q-GDH-based monitor performed better with HD and PD patients. CONCLUSIONS Analytical results prove that the GDH-based monitors tolerate a broad BG concentration range, are oxygen independent, have BG specificity, and have minimal interference from hematocrit. The GDH-based monitors are reliable for multi-patient use.
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Affiliation(s)
- Ta-Yu Huang
- R&D Department, Bionime Corporation, Taichung, Taiwan
| | - Hui-Wen Chang
- Department of Laboratory Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Mei-Fen Tsao
- Department of Laboratory Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | | | - Chih-Chin Ni
- R&D Department, Bionime Corporation, Taichung, Taiwan
| | - Jun-Wei Sue
- R&D Department, Bionime Corporation, Taichung, Taiwan
| | - Hsiu-Chen Lin
- Department of Laboratory Medicine, Taipei Medical University Hospital, Taipei, Taiwan; Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Cheng-Teng Hsu
- School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan.
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24
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Freckmann G, Baumstark A, Schmid C, Pleus S, Link M, Haug C. Evaluation of 12 blood glucose monitoring systems for self-testing: system accuracy and measurement reproducibility. Diabetes Technol Ther 2014; 16:113-22. [PMID: 24205978 DOI: 10.1089/dia.2013.0208] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Systems for self-monitoring of blood glucose (SMBG) have to provide accurate and reproducible blood glucose (BG) values in order to ensure adequate therapeutic decisions by people with diabetes. MATERIALS AND METHODS Twelve SMBG systems were compared in a standardized manner under controlled laboratory conditions: nine systems were available on the German market and were purchased from a local pharmacy, and three systems were obtained from the manufacturer (two systems were available on the U.S. market, and one system was not yet introduced to the German market). System accuracy was evaluated following DIN EN ISO (International Organization for Standardization) 15197:2003. In addition, measurement reproducibility was assessed following a modified TNO (Netherlands Organization for Applied Scientific Research) procedure. Comparison measurements were performed with either the glucose oxidase method (YSI 2300 STAT Plus™ glucose analyzer; YSI Life Sciences, Yellow Springs, OH) or the hexokinase method (cobas(®) c111; Roche Diagnostics GmbH, Mannheim, Germany) according to the manufacturer's measurement procedure. RESULTS The 12 evaluated systems showed between 71.5% and 100% of the measurement results within the required system accuracy limits. Ten systems fulfilled with the evaluated test strip lot minimum accuracy requirements specified by DIN EN ISO 15197:2003. In addition, accuracy limits of the recently published revision ISO 15197:2013 were applied and showed between 54.5% and 100% of the systems' measurement results within the required accuracy limits. Regarding measurement reproducibility, each of the 12 tested systems met the applied performance criteria. CONCLUSIONS In summary, 83% of the systems fulfilled with the evaluated test strip lot minimum system accuracy requirements of DIN EN ISO 15197:2003. Each of the tested systems showed acceptable measurement reproducibility. In order to ensure sufficient measurement quality of each distributed test strip lot, regular evaluations are required.
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Affiliation(s)
- Guido Freckmann
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH an der Universität Ulm , Ulm, Germany
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25
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Schmid C, Haug C, Heinemann L, Freckmann G. System accuracy of blood glucose monitoring systems: impact of use by patients and ambient conditions. Diabetes Technol Ther 2013; 15:889-96. [PMID: 23883407 DOI: 10.1089/dia.2013.0047] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
For self-monitoring of blood glucose by people with diabetes, the reliability of the measured blood glucose values is a prerequisite in order to ensure correct therapeutic decisions. Requirements for system accuracy are defined by the International Organization for Standardization (ISO) in the standard EN ISO 15197:2003. However, even a system with high analytical quality is not a guarantee for accurate and reliable measurement results. Under routine life conditions, blood glucose measurement results are affected by several factors. First, the act of performing measurements as well as the handling of the system may entail numerous possible error sources, such as traces of glucose-containing products on the fingertips, the use of deteriorated test strips, or the incorrect storage of test strips. Second, ambient and sampling conditions such as high altitude, partial pressure of oxygen, ambient temperature, and the use of alternate test sites can have an influence on measurement results. Therefore, the user-friendliness of a system and the quality of the manufacturer's labeling to reduce the risk of handling errors are also important aspects in ensuring reliable and accurate measurement results. In addition, the analytical performance of systems should be less prone to user errors and ambient conditions. Finally, people with diabetes must be aware of the information and instructions in the manufacturer's labeling and must be able to measure and interpret blood glucose results correctly.
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Affiliation(s)
- Christina Schmid
- 1 Institute for Diabetes-Technology GmbH at Ulm University , Ulm, Germany
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26
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Schnell O, Erbach M, Wintergerst E. Higher accuracy of self-monitoring of blood glucose in insulin-treated patients in Germany: clinical and economical aspects. J Diabetes Sci Technol 2013; 7:904-12. [PMID: 23911172 PMCID: PMC3879755 DOI: 10.1177/193229681300700413] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Accuracy standards of blood glucose (BG) meters are currently under review. Revised standards are expected to tighten accuracy requirements. Regarding clinical and financial impact of BG meter accuracy, very little data are available. The aim of this study was to analyze potential cost savings related to higher accuracy of glucose meters in Germany. METHODS As a model for calculation, a reduction of meter error from 20% to 5% was applied. The health economic analysis was based on four main pillars: (1) number of insulin-treated patients; (2) costs for glucose monitoring in Germany; (3) data of a modeling analysis on the impact on hypoglycemic episodes, glycosylated hemoglobin (HbA1c), and, subsequently, myocardial infarctions; and (4) costs of diabetes-related complications in Germany. A reduction of meter error from 20% to 5% was identified to be associated with a 10% reduction in severe hypoglycemic episodes and a 0.39% reduction in HbA1c, which translates into a 0.5% reduction of myocardial infarctions. RESULTS According to the health economic analysis, the reduction in severe hypoglycemic episodes and myocardial infarctions led to cost savings of €24.14 per patient per year. Considering 390,000 type 1 diabetes patients or 2.3 million insulin-treated patients in Germany, these savings could be equal to a reduction in health care expenditures of more than €9.4 million and €55.5 million, respectively. CONCLUSIONS Potential cost savings and clinical effects due to higher accuracy of BG meters should provide an impetus to implementation of tighter accuracy standards and development of glucose meters that provide highest possible accuracy.
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Affiliation(s)
- Oliver Schnell
- Forschergruppe Diabetes e.V., Helmholtz Center Munich, Munich-Neuherberg, Germany.
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27
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Thorpe GH. Assessing the quality of publications evaluating the accuracy of blood glucose monitoring systems. Diabetes Technol Ther 2013; 15:253-9. [PMID: 23413939 PMCID: PMC3696921 DOI: 10.1089/dia.2012.0265] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Many studies determine the performance of blood glucose monitoring (BG) systems. Correct evaluation is, however, complex, and apparent contradiction of results creates confusion. This study aimed to provide an overview of frequently made errors and to develop easy-to-use checklists to verify the quality of such studies. Building on the work from Mahoney and Ellison and subsequent re-evaluation, study designs of accuracy studies were assessed, and best practice and internationally accepted norms were determined. Key issues were collated, and two simplified checklists were developed: one for the assessment of analytical accuracy studies and a second for guidance with studies assessing the influence of interferences. The checklists have been used in a feasibility study with 20 representative studies selected from a literature search between 2007 and 2012. This check revealed that limitations in the designs and methods of studies assessing the performance of BG systems are common. The use of the accuracy checklist with the 20 representative studies showed that only 20% were in agreement with most of the issues deemed important and that 40% showed clear nonconcordance with ISO 15197. The use of the interference checklist showed that only 50% of the publications were in good agreement with the quality checks. In agreement with previous studies, which concluded many evaluations are performed poorly and present questionable conclusions, the use of these checklists demonstrated that few publications adhered to international guidelines and recommendations. Taking this into consideration, it becomes obvious that the publications must be examined in more detail to establish their quality and the validity of conclusions drawn.
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Affiliation(s)
- Gary H Thorpe
- Gary Thorpe Associates Ltd., Birmingham, United Kingdom.
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28
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Pleitez MA, Lieblein T, Bauer A, Hertzberg O, von Lilienfeld-Toal H, Mäntele W. In vivo noninvasive monitoring of glucose concentration in human epidermis by mid-infrared pulsed photoacoustic spectroscopy. Anal Chem 2012; 85:1013-20. [PMID: 23214424 DOI: 10.1021/ac302841f] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The noninvasive determination of glucose in the interstitial layer of the human skin by mid-infrared spectroscopy is reported. The sensitivity for this measurement was obtained by combining the high pulse energy from an external cavity quantum cascade laser (EC-QCL) tunable in the infrared glucose fingerprint region (1000-1220 cm(-1)) focused on the skin, with a detection of the absorbance process by photoacoustic spectroscopy in the ultrasound region performed by a gas cell coupled to the skin. This combination facilitates a quantitative measurement for concentrations of skin glucose in the range from <50 mg/dL to >300 mg/dL, which is the relevant range for the glucose monitoring in diabetes patients. Since the interstitial fluid glucose level is representative of the blood glucose level and follows it without significant delay (<10 min), this method could be applied to establish a noninvasive, painless glucose measurement procedure that is urgently awaited by diabetes patients. We report here the design of the photoacoustic experiments, the spectroscopy of glucose in vivo, and the calibration method for the quantitative determination of glucose in skin. Finally, a preliminary test with healthy volunteers and volunteers suffering from diabetes mellitus demonstrates the viability of a noninvasive glucose monitoring for patients based on the combination of infrared QCL and photoacoustic detection.
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Affiliation(s)
- Miguel A Pleitez
- Institut für Biophysik, Goethe-Universität Frankfurt, Max von Laue-Strasse 1, 60438 Frankfurt am Main, Germany
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Freckmann G, Schmid C, Baumstark A, Pleus S, Link M, Haug C. System accuracy evaluation of 43 blood glucose monitoring systems for self-monitoring of blood glucose according to DIN EN ISO 15197. J Diabetes Sci Technol 2012; 6:1060-75. [PMID: 23063032 PMCID: PMC3570840 DOI: 10.1177/193229681200600510] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND The accuracy of systems for self-monitoring of blood glucose is important, as reliable measurement results are a prerequisite for therapeutic decisions. METHODS This system accuracy evaluation study was performed according to DIN EN ISO 15197:2003 for 43 Conformité Européenne (CE)-labeled blood glucose (BG) monitoring systems. Measurement results of each system were compared with results of the designated comparison method (manufacturer's measurement procedure): glucose oxidase method (YSI 2300 glucose analyzer) or hexokinase method (Hitachi 917/ cobas 501). RESULTS Complete assessment according to the International Organization for Standardization (ISO) standard was performed for 34 out of 43 systems, and 27 (79.4%) meet the requirements of the standard, i.e., ≥95% of their results showed at least the minimum acceptable accuracy. For 9 of the 43 systems, complete accuracy assessment was not performed due to an oxygen sensitivity (manufacturer's labeling). The bias (according to Bland and Altman) of all 43 evaluated systems ranged from -14.1% to +12.4%. CONCLUSIONS From the 34 systems completely assessed, 7 systems did not fulfill the minimal accuracy requirements of the ISO standard. The CE mark apparently does not guarantee that all BG systems provide accuracy according to the standard. Because inaccurate systems bear the risk of false therapeutic decisions, regular and standardized evaluation of BG meters and test strips should be requested in order to ensure adherence to quality standards.
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Affiliation(s)
- Guido Freckmann
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH an der Universität Ulm, Ulm, Germany.
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Baumstark A, Pleus S, Schmid C, Link M, Haug C, Freckmann G. Lot-to-lot variability of test strips and accuracy assessment of systems for self-monitoring of blood glucose according to ISO 15197. J Diabetes Sci Technol 2012; 6:1076-86. [PMID: 23063033 PMCID: PMC3570841 DOI: 10.1177/193229681200600511] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Accurate and reliable blood glucose (BG) measurements require that different test strip lots of the same BG monitoring system provide comparable measurement results. Only a small number of studies addressing this question have been published. METHODS In this study, four test strip lots for each of five different BG systems [Accu-Chek® Aviva (system A), FreeStyle Lite® (system B), GlucoCheck XL (system C), Pura™/mylife™ Pura (system D), and OneTouch® Verio™ Pro (system E)] were evaluated with procedures according to DIN EN ISO 15197:2003. The BG system measurement results were compared with the manufacturer's measurement procedure (glucose oxidase or hexokinase method). Relative bias according to Bland and Altman and system accuracy according to ISO 15197 were analyzed. A BG system consists of the BG meter itself and the test strips. RESULTS The maximum lot-to-lot difference between any two of the four evaluated test strip lots per BG system was 1.0% for system E, 2.1% for system A, 3.1% for system C, 6.9% for system B, and 13.0% for system D. Only two systems (systems A and B) fulfill the criteria of DIN EN ISO 15197:2003 with each test strip lot. CONCLUSIONS Considerable lot-to-lot variability between test strip lots of the same BG system was found. These variations add to other sources of inaccuracy with the specific BG system. Manufacturers should regularly and effectively check the accuracy of their BG meters and test strips even between different test strip lots to minimize risk of false treatment decisions.
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Affiliation(s)
- Annette Baumstark
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH an der Universität Ulm, Ulm, Germany.
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Bratlie KM, York RL, Invernale MA, Langer R, Anderson DG. Materials for diabetes therapeutics. Adv Healthc Mater 2012; 1:267-84. [PMID: 23184741 PMCID: PMC3899887 DOI: 10.1002/adhm.201200037] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Indexed: 11/10/2022]
Abstract
This review is focused on the materials and methods used to fabricate closed-loop systems for type 1 diabetes therapy. Herein, we give a brief overview of current methods used for patient care and discuss two types of possible treatments and the materials used for these therapies-(i) artificial pancreases, comprised of insulin producing cells embedded in a polymeric biomaterial, and (ii) totally synthetic pancreases formulated by integrating continuous glucose monitors with controlled insulin release through degradable polymers and glucose-responsive polymer systems. Both the artificial and the completely synthetic pancreas have two major design requirements: the device must be both biocompatible and be permeable to small molecules and proteins, such as insulin. Several polymers and fabrication methods of artificial pancreases are discussed: microencapsulation, conformal coatings, and planar sheets. We also review the two components of a completely synthetic pancreas. Several types of glucose sensing systems (including materials used for electrochemical, optical, and chemical sensing platforms) are discussed, in addition to various polymer-based release systems (including ethylene-vinyl acetate, polyanhydrides, and phenylboronic acid containing hydrogels).
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Affiliation(s)
- Kaitlin M. Bratlie
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 32 Vassar St., Cambridge, MA 02142, USA
- Department of Anesthesiology, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Roger L. York
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 32 Vassar St., Cambridge, MA 02142, USA
- Department of Anesthesiology, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Michael A. Invernale
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 32 Vassar St., Cambridge, MA 02142, USA
- Department of Anesthesiology, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Robert Langer
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 32 Vassar St., Cambridge, MA 02142, USA
- Department of Anesthesiology, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Harvard-MIT Division of Health Science Technology, Massachusetts Institute of Technology, 45 Carleton Street, Building E25-342, Cambridge, MA 02142, USA
| | - Daniel G. Anderson
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 32 Vassar St., Cambridge, MA 02142, USA
- Department of Anesthesiology, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Harvard-MIT Division of Health Science Technology, Massachusetts Institute of Technology, 45 Carleton Street, Building E25-342, Cambridge, MA 02142, USA
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Cha R, Wang D, He Z, Ni Y. Development of cellulose paper testing strips for quick measurement of glucose using chromogen agent. Carbohydr Polym 2012. [DOI: 10.1016/j.carbpol.2012.02.028] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tack C, Pohlmeier H, Behnke T, Schmid V, Grenningloh M, Forst T, Pfützner A. Accuracy evaluation of five blood glucose monitoring systems obtained from the pharmacy: a European multicenter study with 453 subjects. Diabetes Technol Ther 2012; 14:330-7. [PMID: 22176154 PMCID: PMC3317395 DOI: 10.1089/dia.2011.0170] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND This multicenter study was conducted to evaluate the performance of five recently introduced blood glucose (BG) monitoring (BGM) devices under daily routine conditions in comparison with the YSI (Yellow Springs, OH) 2300 Stat Plus glucose analyzer. METHODS Five hundred one diabetes patients with experience in self-monitoring of BG were randomized to use three of five different BGM devices (FreeStyle Lite® [Abbott Diabetes Care Inc., Alameda, CA], FreeStyle Freedom Lite [Abbott Diabetes Care], OneTouch® UltraEasy® [LifeScan Inc., Milpitas, CA], Accu-Chek® Aviva [Roche Diagnostics, Mannheim, Germany], and Contour® [Bayer Vital GmbH, Leverkusen, Germany]) in a daily routine setting. All devices and strips were purchased from local regular distribution sources (pharmacies, four strip lots per device). The patients performed the finger prick and the glucose measurement on their own. In parallel, a healthcare professional performed the glucose assessment with the reference method (YSI 2300 Stat Plus). The primary objective was the comparison of the mean absolute relative differences (MARD). Secondary objectives were compliance with the International Organization for Standardization (ISO) accuracy criteria under these routine conditions and Clarke and Parkes Error Grid analyses. RESULTS MARD ranged from 4.9% (FreeStyle Lite) to 9.7% (OneTouch UltraEasy). The ISO 15197:2003 requirements were fulfilled by the FreeStyle Lite (98.8%), FreeStyle Freedom Lite (97.5%), and Accu-Chek Aviva (97.0%), but not by the Contour (92.4%) and OneTouch UltraEasy (91.1%). The number of values in Zone A of the Clarke Error Grid analysis was highest for the FreeStyle Lite (98.8%) and lowest for the OneTouch Ultra Easy (90.4%). CONCLUSIONS FreeStyle Lite, FreeStyle Freedom Lite, and Accu-Chek Aviva performed very well in this study with devices and strips purchased through regular distribution channels, with the FreeStyle Lite achieving the lowest MARD in this investigation.
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Affiliation(s)
- Cornelius Tack
- Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Guerra S, Facchinetti A, Sparacino G, Nicolao GD, Cobelli C. Enhancing the accuracy of subcutaneous glucose sensors: a real-time deconvolution-based approach. IEEE Trans Biomed Eng 2012; 59:1658-69. [PMID: 22481799 DOI: 10.1109/tbme.2012.2191782] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Minimally invasive continuous glucose monitoring (CGM) sensors can greatly help diabetes management. Most of these sensors consist of a needle electrode, placed in the subcutaneous tissue, which measures an electrical current exploiting the glucose-oxidase principle. This current is then transformed to glucose levels after calibrating the sensor on the basis of one, or more, self-monitoring blood glucose (SMBG) samples. In this study, we design and test a real-time signal-enhancement module that, cascaded to the CGM device, improves the quality of its output by a proper postprocessing of the CGM signal. In fact, CGM sensors measure glucose in the interstitium rather than in the blood compartment. We show that this distortion can be compensated by means of a regularized deconvolution procedure relying on a linear regression model that can be updated whenever a pair of suitably sampled SMBG references is collected. Tests performed both on simulated and real data demonstrate a significant accuracy improvement of the CGM signal. Simulation studies also demonstrate the robustness of the method against departures from nominal conditions, such as temporal misplacement of the SMBG samples and uncertainty in the blood-to-interstitium glucose kinetic model. Thanks to its online capabilities, the proposed signal-enhancement algorithm can be used to improve the performance of CGM-based real-time systems such as the hypo/hyper glycemic alert generators or the artificial pancreas.
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Affiliation(s)
- Stefania Guerra
- Department of Information Engineering, University of Padova, Padova 35137, Italy.
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