"Norwegian community pharmacies can perform IQC and EQA on a HbA1c POC instrument, and the performance is comparable with that of GP offices. The compliance in the EQA surveys was modest, but the duration of the study and participation in the EQA program was probably too short to implement all the new procedures for all pharmacies."

"The high rate of undiagnosed prediabetes and diabetes among PEH reflects at least what is already seen in the general population in Canada. More resources are required to reduce the barriers to screening for diabetes among this population."

"Better multidimensional sleep health is associated with lower depressive symptoms among African American adults with type 2 diabetes. Longitudinal research is needed to determine the causal association between multidimensional sleep health and depressive symptoms in this population."

"A robust user-friendly postal HbA1c system has been created and successfully integrated into clinical practice using the existing POC equipment at the diabetes center. It provides accurate HbA1c results and is an invaluable tool for remote monitoring of HbA1c in PWD-both during and after the pandemic."

"POC HbA1c testing in community settings was associated with significantly lower HbA1c values when compared with laboratory-measured referrals. Acknowledging effects of regression to the mean, we found that these differences were also associated with POC method, location, individual patient factors and time between measurements. Compared with POC HbA1c values in the NDH range, normoglycemic POC HbA1c values were associated with lower subsequent intervention attendance."

The hemoglobin variant Hb N-Baltimore significantly impairs HbA1c measurement depending on the methodology used. While immunoassays remain relatively accurate, chromatographic methods lead to an underestimation of glucose levels, and capillary electrophoresis fails to produce a result entirely. Clinical inconsistencies between self-monitoring and laboratory HbA1c should prompt immediate investigation using an alternative analytical method to ensure patient safety.

"High rates of pre-diabetes and DM were found in adult TB patients. This study supports the need for routine screening of all patients with TB for DM in Kenya."

"Calibration of laboratory devices by specimens with IFCC-assigned values and by external mathematical calibration could improve the accuracy of POCT HbA 1c measurements. Also, standardized training could improve precision in POCT HbA 1c measurements, especially for semiautomated HbA 1c POCT devices."

"HbA1c POC testing in QAAMS has remained analytically sound, matched the quality achieved by Australasian laboratories and met profession-derived analytical goals for 15years."

"Venous or capillary blood can be used in POCT for HbA1c. POCT is ideal for monitoring glucose control and management of diabetes in resource-limited countries such as South Africa."

"Siemens DCA Vantage and Abbott Afinion 2 demonstrated reliable accuracy and usability. In contrast, i-SENS A1Care and HemoCue HbA1c 501 System require cautious interpretation at high HbA1c levels. Ongoing evaluation is critical to ensure the appropriate use of POC devices in diverse clinical settings."

"For the high-performance liquid chromatography (HPLC)-based platforms (Bio-Rad VARIANT II TURBO 2.0 and D-100), relative deviation from expected values was not clinically significant, even at an HbF level of 35%. In contrast, immunoassay (AU5800; Roche Diagnostics cobas c311 and cobas b101; and Siemens Healthineers DCA Vantage) and enzymatic (Alinity c) methods showed clinically significant deviation at HbF levels above 10%. Our data suggest that the HPLC methods tested can be used for the majority of patients with elevated HbF. For patients with HbF levels above 10%, immunoassay and enzymatic methods appear to be unsuitable, and alternative HbA1c methods are still advised."

The Hb Tacoma variant (1 in 1,000 patients) significantly interferes with certain HbA1c monitoring methods, most notably causing a 40% underestimation on the Bio-Rad Variant II due to co-elution. While other chromatographic and electrophoretic methods show either positive bias or poor precision, immunoassays, affinity chromatography, and enzymatic methods remain unaffected. To ensure diagnostic accuracy in these patients, laboratories must identify abnormal chromatograms and switch to these robust alternative platforms.

"A1C self-testing is feasible for use in community settings involving African American adults with T2D. The A1CNow Self-Check underestimated A1C values when compared with the reference standard. Ongoing improvements in point-of-care devices have the potential to expand research and clinical care, especially in underserved communities."

"HbA1c immunoassays DCA-Vantage was comparable to HPLC assay, showing good correlation, appropriate precision and low bias, whereas I-Chroma assay was precise but inaccurate. Therefore, DCA-Vantage has better performance than I-Chroma. These findings suggest that is convenient to assess the HbA1c immunoassays commercially available in our country, Ecuador."

"The POCT methods tested in this study [Afinion™ AS100 Analyzer (Axis-Shield, Oslo Norway) and DCA Vantage™ Analyzer (Siemens Healthcare Diagnostics, Tarrytown NY, US)] showed a good correlation with the laboratory reference method, however, with an overall negative bias."

"Imprecision and bias were not low enough to recommend either POC analyzer [Afinion and DCA Vantage] for HbA1c determinations in this setting."

"All who rely on POC methods [Afinion™ automated boronate affinity assay and the DCA Vantage immunoassay-based POC techniques] as well as on central laboratory measurement of HbA1c must understand the potential limitations of these assays. The assessment of diabetes blood sugar control should proceed from the evaluation of HbA1c combined with review of plasma glucose and of self-monitored blood glucose values."

"Only the Afinion AS100 point-of-care system met all NGSP performance criteria [among the three systems tested Afinion AS100, DCA Vantage and In2it point-of-care systems]."

"A1C POC devices [A1CNow (formerly manufactured by Bayer Diabetes Care but now made by Chek Diagnostics) and two bench-top models called the Axis-Shield Afinion Analyzer and the Siemens DCA Vantage] have improved the quality of diabetes management by offering health care providers a method for timely assessment of diabetes control, which facilitates informed decision making during consultations. Furthermore, A1C POC devices may improve patient adherence by lessening transportation and cost barriers associated with extra office and laboratory visits. The selection of a POC A1C device should be based on accuracy, precision, ease of use, and price, among other considerations."

"Afinion, DCA Vantage, Cobas B101, and B-analyst instruments met the generally accepted performance criteria for Hb A(1c). Quo-Test, Quo-Lab, and InnovaStar met the criteria for precision but not for bias. Proficiency testing should be mandated for users of Hb A1c POC assays to ensure quality."

"External quality assurance (EQA) performance data were available for five HbA1c devices: Abbott Afinion, Bio-Rad D series, Roche Cobas, Sebia Capillarys, and Siemens DCA. The median IRRs were optimal for all methods for diabetes diagnosis (0.11-0.22 %) and for diabetes monitoring (-0.51-1.01 %), with negative IRRs representing lower reclassification rates than the NHANES device. For prediabetes diagnosis, the Afinion failed the minimal standard (8.62 %), but median IRRs were desirable for the other methods (1.43-2.69 %). EQA providers should consider reporting IRR for suitable analytes to help identify poorly performing IVD devices."

The Siemens DCA Vantage™ POC device demonstrated high agreement with laboratory gold standards, yielding coefficients of 0.970 for HbA1c and 0.745 for the albumin-creatinine ratio. These results justify its clinical use as a reliable tool for monitoring glycemic control and detecting early-stage diabetic nephropathy. Implementing this technology in primary and remote care settings can significantly improve the timely diagnosis and management of chronic kidney disease in patients with type-2 diabetes.

"The DCA Vantage™ HbA1c analysis does not fulfil the prevailing analytical performance specifications, but rigorous validation of new reagent lots and continuous recalibration of instruments may potentially improve the precision substantially. Our findings, therefore, clearly emphasise the necessity of a close collaboration between clinicians and laboratory professionals in the POCT field. Finally, POCT HbA1c results should always be interpreted together with other measures of glycaemic control to avoid inappropriate change of patient treatments due to measurement uncertainty."

The study highlights that Hb variants, particularly Hb Riccarton and HbE, can significantly interfere with HbA1c measurements on the Tosoh G11 HPLC system. Hb Riccarton, found to be relatively common in the Danish Caucasian population, presents a unique analytical challenge due to its fluctuating behavior on chromatograms; it oscillates between being separated from and integrated into the HbA1c fraction, leading to inconsistent results.

"This case evidenced an interference on HbA1c test in presence of Hb G-Copenhagen depending to the analyzer used. This report help to alert of such possibility and to remain that a discordance between HbA1c and glycemia can be due to an Hb variant."

Significant discrepancies between laboratory HbA1c and CGM-derived eA1c arise from their differing assessment windows (12 weeks vs. 14 days). As demonstrated in this case, recent glycemic instability - evidenced by an increased labile A1c fraction - creates a gap that can lead to therapeutic errors. Because these markers reflect different timeframes, they are not directly comparable during periods of rapid metabolic change. Clinical interpretation must account for these temporal differences as CGM use becomes standard practice.

"The results from this study indicated that POC testing, including POC HbA1c and RGB, could be used as a potential tool for screening of subjects with potential type 2 DM and AGR in a dental setting."

Point-of-care HbA1c testing shows a high level of agreement with laboratory standards in the preoperative outpatient setting, as evidenced by a minimal bias of measurements falling within the clinically accurate Zone A of Clarke’s error grid. These findings validate the use of POC devices for immediate, reliable glycemic screening in patients at risk for cardiometabolic complications, allowing for efficient preoperative risk profiling without laboratory delays.

"There is a consistent negative bias with POC testing, most pronounced in the female and pediatric populations. Further studies will determine what variables contribute to this discrepancy and how clinical management is modified. POC testing using the DCA Vantage should be interpreted cautiously."

"This study does not support the introduction of POC testing for HbA1c in public sector primary care practice in the current context. POC testing should be evaluated further in combination with interventions to overcome clinical inertia and strengthen primary healthcare."

"Replacing laboratory HbA1c measurement with point-of-care HbA1c testing or using point-of-care HbA1c testing in combination with laboratory HbA1c measurement to monitor glycemic control in patients with diabetes could have saved the province $1,175,620 to $4,702,481 in 2013/2014."