Limitations of glycated albumin standardization when applied to the assessment of diabetes patients.

Objectives: Glycated albumin (GA) has potential value in the management of people with diabetes; however, to draw meaningful conclusions between clinical studies it is important that the GA values are comparable. This study investigates the standardization of the Norudia Glycated Albumin and Lucica Glycated Albumin-L methods.

Methods: The manufacturer reported imprecision was verified by performing CLSI-EP15-A3 protocol using manufacturer produced controls.

Innovations in HbA analysis: finding the balance between speed and accuracy. An investigation of a potential new Secondary Reference Measurement Procedure for the IFCC.

Objectives: The escalating prevalence of diabetes worldwide has resulted in a dramatic increase in the number of people who need testing, which in turn necessitates faster HbA measurement. The Tosoh GR01 addresses the need for fast turnaround times of whilst offering pragmatic steps to maintain result accuracy in a single instrument by offering two distinct operating modes: Short Mode (SM) and Long Mode (LM). The aim of this study was to evaluate all relevant aspects of the performance of the Tosoh GR01 with a view to accepting the instrument as a future Secondary Reference Measurement Procedure (SRMP) for the IFCC.

Are hemoglobin A point-of-care analyzers fit for purpose? The story continues.

Objectives: Point-of-care (POC) analyzers are playing an increasingly important role in diabetes management but it is essential that we know the performance of these analyzers in order to make appropriate clinical decisions. Whilst there is a growing body of evidence around the more well-known analyzers, there are many 'new kids on the block' with new features, such as displaying the presence of potential Hb-variants, which do not yet have a proven track record.

Methods: The study is a comprehensive analytical and usability study of six POC analyzers for HbA using Clinical and Laboratory Standards Institute (CLSI) protocols, international quality targets and certified International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and National Glycohemoglobin Standardization Program (NGSP) Secondary Reference Measurement Procedures (SRMP).

Analysis: Investigating the quality of POCT devices for HbA1c, what are our next steps?

There are a growing number of publications evaluating the performance of HbA1c point-of-care testing (POCT) devices when compared to routine laboratory instruments, but is this what we need from future studies? Here we describe the current understanding of the performance of POCT for HbA1c, which areas need further studies, and the key requirements for future publications based on performance evaluations of these devices. These include studies in clinical settings, performance measured against internationally standardized reference methods, and the need to evaluate new to the market devices that do not currently have a detailed performance history. In addition we highlight the need for external quality assessment schemes that are designed to support POCT in a wide range of clinical settings.

HbA1c method performance: The great success story of global standardization.

Diagnosing and monitoring the treatment of people with diabetes is a global issue and uses considerable resources in laboratories and clinics worldwide. Hemoglobin A1c (HbA1c) has been the mainstay of monitoring glycemic control in people with diabetes for many years and more recently it has been advocated as a diagnostic tool for type 2 diabetes mellitus (T2DM). Good analytical performance is key to the successful use of any laboratory test, but is critical when using the test to diagnose disease, especially when the potential number of diagnoses could exceed 500 million people.

Evaluation of Four HbA1c Point-of-Care Devices Using International Quality Targets: Are They Fit for the Purpose?

Background: Point-of-care (POC) testing is becoming increasingly valuable in health care delivery, and it is important that the devices used meet the same quality criteria as main laboratory analyzers. While external quality assessment (EQA) provides a great tool for assessing quality, many POC devices are not enrolled in these schemes and standard laboratory evaluations are needed to assess performance.

Methods: The Clinical and Laboratory Standards Institute (CLSI) protocols EP-5 and EP-9 were applied to investigate imprecision, accuracy and bias.

Evaluating new HbA1c methods for adoption by the IFCC and NGSP reference networks using international quality targets.

Background: As a reference laboratory for HbA1c, it is essential to have accurate and precise HbA1c methods covering a range of measurement principles. We report an evaluation of the Abbott Enzymatic (Architect c4000), Roche Gen.3 HbA1c (Cobas c513) and Tosoh G11 using different quality targets.

Understanding the Use of Sigma Metrics in Hemoglobin A1c Analysis.

This study uses three unique data sets to show the state of the art of hemoglobin A1c (HbA1c) analyzers in a range of settings and compares their performance against the international guidance set by the International Federation of Clinical Chemistry and Laboratory Medicine task force for HbA1c standardization. The data are used to show the effect of tightening those criteria, and the study serves as a guide to the practical implementation of the sigma-metrics approach in a range of clinical settings.

Whole Blood Donation Affects the Interpretation of Hemoglobin A1c.

Introduction: Several factors, including changed dynamics of erythrocyte formation and degradation, can influence the degree of hemoglobin A1c (HbA1c) formation thereby affecting its use in monitoring diabetes. This study determines the influence of whole blood donation on HbA1c in both non-diabetic blood donors and blood donors with type 2 diabetes.

Methods: In this observational study, 23 non-diabetic blood donors and 21 blood donors with type 2 diabetes donated 475 mL whole blood and were followed prospectively for nine weeks.

Can the Afinion HbA1c Point-of-Care instrument be an alternative method for the Tosoh G8 in the case of Hb-Tacoma?

Background: Hb-variant interference when reporting HbA1c has been an ongoing challenge since HbA1c was introduced to monitor patients with diabetes mellitus. Most Hb-variants show an abnormal chromatogram when cation-exchange HPLC is used for the determination of HbA1c. Unfortunately, the Tosoh G8 generates what appears to be normal chromatogram in the presence of Hb-Tacoma, yielding a falsely high HbA1c value.

Investigation of 2 models to set and evaluate quality targets for hb a1c: biological variation and sigma-metrics.

Background: A major objective of the IFCC Task Force on Implementation of HbA1c Standardization is to develop a model to define quality targets for glycated hemoglobin (Hb A1c).

Methods: Two generic models, biological variation and sigma-metrics, are investigated. We selected variables in the models for Hb A1c and used data of external quality assurance/proficiency testing programs to evaluate the suitability of the models to set and evaluate quality targets within and between laboratories.

Multicentre evaluation of the Premier Hb9210 HbA1c analyser.

Background: The accurate and precise quantification of HbA1c is essential for the diagnosis and routine monitoring of patients with diabetes. We report an evaluation of the Trinity Biotech Premier Hb9210 analyser (Bray, Ireland/Kansas City, MO, USA), a boronate affinity chromatography-based high performance liquid chromatography (HPLC) system for the measurement of glycated haemoglobin.

Methods: We evaluated the analytical performance of the Hb9210 as part of a multicentre evaluation.

Three of 7 hemoglobin A1c point-of-care instruments do not meet generally accepted analytical performance criteria.

Background: In 2009, we investigated the conformance of 8 hemoglobin A(1c) (Hb A(1c)) point-of-care (POC) instruments. Since then, instruments have improved and new devices are available on the market. In this second study, we evaluated the performance of DCA Vantage, Afinion, InnovaStar, Quo-Lab, Quo-Test, Cobas B101, and B-analyst Hb A(1c) POC instruments.

Haemoglobin A1c: Historical overview and current concepts.

Since the discovery of the relation between increased concentrations of fast haemoglobin fractions in patients with diabetes mellitus compared to concentrations in subjects without diabetes mellitus by Samuel Rahbar and co-workers in 1969, glycated haemoglobin A1c (HbA1c) has become a "gold standard" for glucose management in patients with diabetes mellitus. Recently, HbA1c has been advocated as a diagnostic marker for diabetes mellitus, which further underlines the importance of HbA1c. There are currently more than 30 methods available on the market with an analytical performance ranging from poor to state of the art.

One in five laboratories using various hemoglobin A1c methods do not meet the criteria for optimal diabetes care management.

Background: We assessed the reference change value (RCV) of currently available hemoglobin A(1c) (HbA(1c)) laboratory assays, which is defined as the critical difference between two consecutive HbA(1c) measurements representing a significant change in health status.

Methods: We examined the individual laboratory coefficients of variation (CVs) in the Dutch/Belgian quality scheme based on 24 lyophilized samples and calculated the RCV per laboratory (n = 220) and per assay method. In addition, two pooled whole blood samples were sent to the participating laboratories.

Evaluation of the Menarini/ARKRAY ADAMS A1c HA-8180V analyser for HbA1c.

Background: We report an evaluation of the Menarini/ARKRAY ADAMS A1c HA-8180V analyser (HA-8180V), the fifth generation Menarini/ARKRAY ion-exchange HPLC for the measurement of HbA(1c).

Methods: We evaluated the analytical performance, the measurement of haemoglobin variants and the performance in comparison to major analytical methods.

Results: Within-run, between-run and total CV were 0.

Hemoglobin A1c point-of-care assays; a new world with a lot of consequences!

Background: Point-of-care instruments for the measurement of hemoglobin A1c (HbA1c) may improve the glycemic control of people with diabetes by providing a rapid result if the performance of the instruments used is acceptable. A 0.5% HbA1c difference between successive results is considered a clinically relevant change.