Introduction of a Novel Smartphone-Coupled Blood Glucose Monitoring System.

The novel system for self-monitoring of blood glucose (SMBG) PixoTest couples SMBG to a smartphone and does not require a separate glucose meter. The integrated system includes all components necessary for a glucose measurement, and owing to a colorimetric measurement principle, a smartphone camera can capture color changes and a software app calculates the corresponding glucose value. In the presented study, the system was evaluated in terms of system accuracy as described in ISO 15197:2013. It was shown to fulfill system accuracy requirements with 97-99% of results from three different reagent system lots within the accuracy limits and 100% of results within zone A of the consensus error grid.

Accuracy Evaluation of Four Blood Glucose Monitoring Systems in the Hands of Intended Users and Trained Personnel Based on ISO 15197 Requirements.

BACKGROUND: Self-monitoring of blood glucose (BG) is an integral part in the therapy of people with diabetes, which is why blood glucose monitoring systems (BGMS) have to fulfill minimum accuracy requirements. However, accuracy is often assessed by trained operators, although such assessments do not necessarily allow for drawing conclusions on accuracy in the hands of lay users. METHODS: The accuracy of 4 different BGMS (Accu-Chek® Active, Accu-Chek® Performa, Contour®Plus, and OneTouch® SelectSimple™) in the hands of lay users and trained study personnel was assessed in this study. Procedures were based on International Organization for Standardization (ISO) 15197:2013, clause 8, requirements. BGMS measurement results were compared against results from a glucose oxidase and a hexokinase laboratory analyzer. Handling errors made by lay users were documented. Accuracy was evaluated applying ISO 15197:2013/EN ISO 15197:2015 criteria (percentage of results within ±15 mg/dL or ±15%), more stringent criteria (10 mg/dL or 10%, and 5 mg/dL or 5%, respectively), and ISO 15197:2003 system accuracy criteria. RESULTS: The level of accuracy differed among the four BGMS investigated independent from the operator. One system had less than 95% of the values within each of the limits and one system showed marked differences in accuracy when used by trained personnel and by lay users. Common lay user errors were not checking the test strip codes, incorrect application of blood, and not using the blood drop immediately. CONCLUSIONS: BGMS accuracy can differ when used by trained personnel and when used by lay users. It is important that BGMS manufacturers provide systems that are as insensitive to operator errors as technically possible and easy to use.

Performance of two updated blood glucose monitoring systems: an evaluation following ISO 15197:2013.

Objective For patients with diabetes, regular self-monitoring of blood glucose (SMBG) is essential to ensure adequate glycemic control. Therefore, accurate and reliable blood glucose measurements with SMBG systems are necessary. The international standard ISO 15197 describes requirements for SMBG systems, such as limits within which 95% of glucose results have to fall to reach acceptable system accuracy. The 2013 version of this standard sets higher demands, especially regarding system accuracy, than the currently still valid edition. ISO 15197 can be applied by manufacturers to receive a CE mark for their system. Research design and methods This study was an accuracy evaluation following ISO 15197:2013 section 6.3 of two recently updated SMBG systems (Contour * and Contour TS; Bayer Consumer Care AG, Basel, Switzerland) with an improved algorithm to investigate whether the systems fulfill the requirements of the new standard. For this purpose, capillary blood samples of approximately 100 participants were measured with three test strip lots of both systems and deviations from glucose values obtained with a hexokinase-based comparison method (Cobas Integra † 400 plus; Roche Instrument Center, Rotkreuz, Switzerland) were determined. Percentages of values within the acceptance criteria of ISO 15197:2013 were calculated. This study was registered at clinicaltrials.gov (NCT02358408). Main outcome Both updated systems fulfilled the system accuracy requirements of ISO 15197:2013 as 98.5% to 100% of the results were within the stipulated limits. Furthermore, all results were within the clinically non-critical zones A and B of the consensus error grid for type 1 diabetes. Conclusions The technical improvement of the systems ensured compliance with ISO 15197 in the hands of healthcare professionals even in its more stringent 2013 version. Alternative presentation of system accuracy results in radar plots provides additional information with certain advantages. In addition, the surveillance error grid offers a modern tool to assess a system's clinical performance.

System Accuracy Evaluation of Four Systems for Self-Monitoring of Blood Glucose Following ISO 15197 Using a Glucose Oxidase and a Hexokinase-Based Comparison Method.

BACKGROUND: The standard ISO (International Organization for Standardization) 15197 is widely accepted for the accuracy evaluation of systems for self-monitoring of blood glucose (SMBG). Accuracy evaluation was performed for 4 SMBG systems (Accu-Chek Aviva, ContourXT, GlucoCheck XL, GlucoMen LX PLUS) with 3 test strip lots each. To investigate a possible impact of the comparison method on system accuracy data, 2 different established methods were used. METHODS: The evaluation was performed in a standardized manner following test procedures described in ISO 15197:2003 (section 7.3). System accuracy was assessed by applying ISO 15197:2003 and in addition ISO 15197:2013 criteria (section 6.3.3). For each system, comparison measurements were performed with a glucose oxidase (YSI 2300 STAT Plus glucose analyzer) and a hexokinase (cobas c111) method. RESULTS: All 4 systems fulfilled the accuracy requirements of ISO 15197:2003 with the tested lots. More stringent accuracy criteria of ISO 15197:2013 were fulfilled by 3 systems (Accu-Chek Aviva, ContourXT, GlucoMen LX PLUS) when compared to the manufacturer's comparison method and by 2 systems (Accu-Chek Aviva, ContourXT) when compared to the alternative comparison method. All systems showed lot-to-lot variability to a certain degree; 2 systems (Accu-Chek Aviva, ContourXT), however, showed only minimal differences in relative bias between the 3 evaluated lots. CONCLUSIONS: In this study, all 4 systems complied with the evaluated test strip lots with accuracy criteria of ISO 15197:2003. Applying ISO 15197:2013 accuracy limits, differences in the accuracy of the tested systems were observed, also demonstrating that the applied comparison method/system and the lot-to-lot variability can have a decisive influence on accuracy data obtained for a SMBG system.

Relationship between allergy and cancer: an overview.

Allergic diseases and malignancies cause a lot of morbidity, mortality and high costs for healthcare systems. An inverse association between allergy and cancer has been suspected for a long time, but even despite extensive research no general relationship has been determined. This review comprises 32 epidemiological studies published between 1960 and 2011 and draws conclusions regarding relationships between specific types of cancer and allergic diseases. On the one hand, inflammatory reactions in the course of allergy can support carcinogenesis but are limited to specific areas, whereas on the other hand systemic effects in terms of enhanced immunosurveillance can prevent cancer.