Effect of immediate hemoglobin A1c results on treatment decisions in office practice

HBA1C point-of-care testing for diabetes control in a low-income population: A before and after study and cost-parity analysis HbA1c point-of-care testing for diabetes control

OBJECTIVE

To evaluate the results of a program that offered access to HbA1c POC tests for the glycemic control of patients with diabetes in small and poor municipalities of Minas Gerais, Brazil.

METHODS

Using a before and after study, we compared four groups: patients submitted to (i) POC tests; (ii) conventional tests; (iii) both tests; and (iv) neither test. The analysis considered three periods: before the program; before the pandemic; and during the pandemic. A cost comparison was conducted under the societal perspective and a cost-parity model was designed.

RESULTS

1349 patients previously diagnosed with diabetes were included in the analysis. The rate of consultations and the rate of HbA1c testing were significantly different between all periods and groups. Group iii had a much higher consultation and testing rate. The costs were around 89.45 PPP-USD for POC tests and between 32.44 and 54.66 PPP-USD for conventional tests. Cost-parity analysis suggests that the technology would be acceptable if the annual number of tests was between 247 and 771.

CONCLUSION

Using POC devices improved access to HbA1c testing but not glycemic control. Even in small towns, the number of tests necessary to achieve cost-parity is low enough to enable their incorporation into the public health system.

Utilizing point-of-care A1c to impact outcomes - can we make it happen in primary care?

PURPOSE OF REVIEW

Hemoglobin A1c testing provides a marker of glycemic control and is the standard for diabetes risk assessment. According to the Centers for Disease Control (CDC), only 67.3-71.4% of diabetic patients between 2011 and 2016 had at least two A1c levels tested per year. Moreover, 27.8% had uncontrolled diabetes with an A1c of ≥8.0%, increasing the risk of microvascular complications. Lack of monitoring presents a significant barrier, and improving ease of testing could improve glycemic control.

RECENT FINDINGS

Point-of-care (POC) A1c testing, obtained via capillary blood with results provided in 5-6 min, is available and used frequently in endocrine clinics. However, POC A1c testing is not standard in primary care, where 90% of type 2 diabetes patients are treated. Barriers include access and costs of POC A1c machines and standardization of testing in the primary care setting. Review of literature, however, suggests that POC A1c testing in primary care may lead to A1c reduction whereas being potentially cost-effective and strengths the patient-physician relationship.

SUMMARY

POC A1c testing in primary care, if widely available and integrated into workflow, has the potential to positively impact diabetes care. Real-time feedback may change patient and physician behaviors, allowing earlier therapeutic intensification.

Primary Care Cluster RCT to Increase Diabetes Prevention Program Referrals

INTRODUCTION

The Diabetes Prevention Program, an intensive lifestyle change program, effectively reduces the risk of progression from prediabetes to type 2 diabetes but is underutilized. An implementation study using formative research was undertaken to increase Diabetes Prevention Program referrals at a primary care clinic.

STUDY DESIGN

A pragmatic, cluster randomized, mixed-methods study.

SETTING/PARTICPANTS

Clusters were teams of primary care clinicians from 2 primary care clinics. The 3 intervention clusters had 8-11 clinicians, and the 3 control clusters had 7-20 clinicians.

INTERVENTION

Implementation activities occurred from December 2017 to February 2019. The activities included targeted clinician education, a prediabetes clinician champion, and a custom electronic health record report identifying patients with prediabetes.

MAIN OUTCOME MEASURES

The primary outcome was referral of patients with prediabetes to the institutional Diabetes Prevention Program. Study data, including patient demographic and clinical variables, came from electronic health record. Interviews with clinicians evaluated the implementation strategies. Generalized estimating equation analyses that accounted for multiple levels of correlation and interview content analysis occurred in 2019.

RESULTS

Study clinicians cared for 2,992 patients with a prediabetes diagnosis or HbA1c indicative of prediabetes (5.7%-6.4%). Clinicians in the intervention clusters referred 6.9% (87 of 1,262) of patients with prediabetes to the Diabetes Prevention Program and those in the control clusters referred 1.5% (26 of 1,730). When adjusted for patient age, sex, race, HbA1c value, HbA1c test location, and insurance type, intervention clinicians had 3.85 (95% CI=0.40, 36.78) greater odds of referring a patient with prediabetes to the Diabetes Prevention Program. The 11 interviewed intervention clinicians had mixed opinions about the utility of the interventions, reporting the prediabetes clinic champion (n=7, 64%) and educational presentations (n=6, 55%) as most helpful.

CONCLUSIONS

Intervention clinicians were more likely to make Diabetes Prevention Program referrals; however, the study lacked power to achieve statistical significance. Clinician interviews suggested that intervention components that triggered Diabetes Prevention Program referrals varied among clinicians.

The value proposition for point-of-care testing in healthcare: HbA1c for monitoring in diabetes management as an exemplar

Point-of-care testing (POCT) is a key enabling technology for disruptive and transformative innovation in healthcare, allowing tests to be performed quickly and close to the patient. This results in faster clinical decision making and new, more efficient models of care, with clinical, process and economic benefits potentially accruing to all stakeholders. Recognised barriers to the adoption of new technology such as POCT include poor understanding of current practice and thus the unmet need, the challenges of process change, and reluctance to disinvest in redundant resources resulting from improved pathway efficiency. Major contributors to this problem include a background of funding, organisation and management of healthcare that fails to recognise the complexity of a multiple stakeholder health economy seeking to become more outcomes-based and value driven. We examine the concept of a structured value proposition as a generic tool to achieve better adoption of POCT using as an example, the evidence that is available for the rapid measurement of glycated haemoglobin (HbA1c) in the management of diabetes. We highlight the key components of the value proposition, identifying the impact of the test result on all stakeholders and the metrics which are required to define current practice (e.g. a laboratory-based HbA1c testing service), in order to develop the business case and the implementation plan required to demonstrate effective adoption of a POCT-based service. We conclude that the value proposition helps to identify the potential benefits to be gained from using POCT, and the stakeholders to whom they accrue.

Point-of-care testing in diabetes management

The prevalence of diabetes mellitus (DM) has rapidly increased over the last decades, reaching epidemic magnitudes, particularly in lowand middle-income countries. Point-of-care (POC) technology enables decision making near or at the site of patient care. Portable blood glucose meters and HbA1c testing are used by the healthcare provider and millions of patients with diabetes to monitor the safety and effectiveness of the diabetes treatment. However, POC capillary blood glucose and POC HbA1c testing are not recommended for diabetes diagnosis. Rather, they have been used for screening diabetes in lowand middle-income countries to decrease the disease burden.

Implementation of HbA1c Point of Care Testing in 3 German Medical Practices: Impact on Workflow and Physician, Staff, and Patient Satisfaction

BACKGROUND

Medical practices face challenges of time and cost pressures with scarce resources. Point-of-care testing (POCT) has the potential to accelerate processes compared to central laboratory testing and can increase satisfaction of physicians, staff members, and patients. The objective of this study was to evaluate the effects of introducing HbA1c POCT in practices specialized in diabetes.

METHOD

Three German practices that manage 400, 550, and 950 diabetes patients per year participated in this evaluation. The workflow and required time before and after POCT implementation (device: Alere Afinion AS100 Analyzer) was evaluated in each practice. Physician (n = 5), staff (n = 9), and patient (n = 298) satisfaction was assessed with questionnaires and interviews.

RESULTS

After POCT implementation the number of required visits scheduled was reduced by 80% (88% vs 17.6%, P < .0001), the number of venous blood collections by 75% (91% vs 23%, P < .0001). Of patients, 82% (vs 13% prior to POCT implementation) were able to discuss their HbA1c values with treating physicians immediately during their first visit ( P < .0001). In two of the practices the POCT process resulted in significant time savings of approximately 20 and 22 working days per 1000 patients per year (95% CI 2-46; 95% CI 10-44). All physicians indicated that POCT HbA1c implementation improved the practice workflow and all experienced a relief of burden for the office and the patients. All staff members indicated that they found the POCT measurement easy to perform and experienced a relief of burden. The majority (61.3%) of patients found the capillary blood collection more pleasant and 83% saw an advantage in the immediate availability of HbA1c results.

CONCLUSIONS

The implementation of HbA1c POCT leads to an improved practice workflow and increases satisfaction of physicians, staff members and patients.

Verification of a novel point-of-care HbA1c device in real world clinical practice by comparison to three high performance liquid chromatography instruments

Introduction

A real world clinical study was designed and conducted to evaluate the performance of a novel point-of-care device for determination of glycated haemoglobin A_1c (HbA_1c), A1C EZ 2.0, in daily clinical practice.

Materials and methods

Five hundred and fourteen subjects were included in this study, and divided into three groups. HbA_1c was measured by A1C EZ 2.0 and three different high performance liquid chromatography (HPLC) devices: Bio-Rad Variant II Turbo, Tosoh HLC-723 G8 and Premier Hb9210 separately. Precision of A1C EZ 2.0 was also evaluated.

Results

Results obtained from A1C EZ 2.0 and all HPLC devices are correlated. Passing-Bablok regression analysis shows the equation of A1C EZ 2.0 results against the mean of HPLC devices with corresponding 95% confidence intervals (95% CI) for the intercept and slope is y = 0.10 (- 0.17 to 0.10) + 1.00 (1.00 to 1.04) x. Bland-Altman difference plot shows that the mean relative difference between A1C EZ 2.0 and Variant II Turbo, G8, Hb9210 and all HPLC results is 2.5%, 0.6%, 0.4% and 1.1%, respectively. In addition, 121 pairs of results determined by using both venous and capillary blood prove that the difference of two kinds of blood sample causes no notable variation when measured by A1C EZ 2.0. Precision study gives 2.3% and 1.9% of total coefficient of variation for normal and abnormal HbA_1c sample in A1C EZ 2.0.

Conclusions

HbA_1c values measured by A1C EZ 2.0 were in good accordance with the results obtained with the reference HPLC devices.

Improving access to HbA1c in sub-Saharan Africa (IA3) cohort: cohort profile

Introduction

Glycated haemoglobin (HbA1c) is the best surrogate of average blood glucose control in diabetic patients, and lowering HbA1c significantly reduces diabetes complications. Moreover, immediate feedback of HbA1c measurement to patients may improve control. However, HbA1c is unavailable in most parts of Africa, a continent with one of the highest burden of diabetes. To translate these evidences, we are conducting a multicentric project in 10 health care facilities in Guinea and Cameroon to evaluate the feasibility and one-year benefit of affordable HbA1c measurement with immediate feedback to patients on diabetes control and related outcomes.

Participants

We consecutively enrolled patients with diabetes mellitus independently of the type of disease. We hypothesised an average 1%-decrease in HbA1c in a 1000-patient study population, with a 20% increase in the number of patients reaching treatment goals within 12 months of intervention and follow-up.

Findings to date

A total of 1, 349 diabetic patients aged 56.2±12.6 years are enrolled (813 in Cameroon and 536 in Guinea) of whom 59.8% are women. The mean duration of diabetes is 7.4±6.3 years and baseline HbA1c is 9.7±2.6% in Guinea and 8.6±2.5% in Cameroon.

Future plans

To investigate whether the introduction of routine HbA1c measurement with immediate feedback to patients and provision of relevant education would improve diabetes control after one year. The impact of the intervention on diabetes associated-complications and mortality warrant further assessment in the long term.

Performance of point-of-care HbA1c test devices: implications for use in clinical practice - a systematic review and meta-analysis

BACKGROUND

Point-of-care (POC) devices could be used to measure hemoglobin A1c (HbA1c) in the doctors' office, allowing immediate feedback of results to patients. Reports have raised concerns about the analytical performance of some of these devices. We carried out a systematic review and meta-analysis using a novel approach to compare the accuracy and precision of POC HbA1c devices.

METHODS

Medline, Embase and Web of Science databases were searched in June 2015 for published reports comparing POC HbA1c devices with laboratory methods. Two reviewers screened articles and extracted data on bias, precision and diagnostic accuracy. Mean bias and variability between the POC and laboratory test were combined in a meta-analysis. Study quality was assessed using the QUADAS2 tool.

RESULTS

Two researchers independently reviewed 1739 records for eligibility. Sixty-one studies were included in the meta-analysis of mean bias. Devices evaluated were A1cgear, A1cNow, Afinion, B-analyst, Clover, Cobas b101, DCA 2000/Vantage, HemoCue, Innovastar, Nycocard, Quo-Lab, Quo-Test and SDA1cCare. Nine devices had a negative mean bias which was significant for three devices. There was substantial variability in bias within devices. There was no difference in bias between clinical or laboratory operators in two devices.

CONCLUSIONS

This is the first meta-analysis to directly compare performance of POC HbA1c devices. Use of a device with a mean negative bias compared to a laboratory method may lead to higher levels of glycemia and a lower risk of hypoglycaemia. The implications of this on clinical decision-making and patient outcomes now need to be tested in a randomized trial.

Systematic Diabetes Screening Using Point-of-Care HbA1c Testing Facilitates Identification of Prediabetes

This prospective longitudinal study compares diabetes screenings between standard practices vs systematically offered point-of-care (POC) hemoglobin A1c (HbA1c) tests in patients aged 45 years or older. Systematically screened participants (n = 164) identified 63% (n = 104) with unknown hyperglycemia and 53% (n = 88) in prediabetes. The standard practice (n = 324) screened 22% (n = 73), most commonly by blood glucose (96%); 8% (n = 6) and 33% (n = 24) were found to have diabetes and prediabetes, respectively. The association between screening outcome and screening method was statistically significant (P = 0.005) in favor of HbA1C HbA1c may be the most effective method to identify patients unknowingly living in hyperglycemia. Point-of-care tests further facilitate screening evaluation in a timely and feasible fashion.

Selecting an A1C Point-of-Care Instrument

A1C point-of-care (POC) instruments benefit patients with diabetes by facilitating clinician decision making that results in significant glycemic improvements. Three National Glycohemoglobin Standardization Program (NGSP)-certified POC products are available in the United States: the handheld 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. This article compares the three available NGSP-certified POC products in terms of accuracy, precision, ease of use, cost, and additional features. Its goal is to aid health care facilities in conveniently identifying the A1C POC product that best meets their needs. It additionally reviews evidence that supports the continued use of A1C POC instruments in the clinical arena.

Performance evaluation of SD A1cCare as a HbA1c analyzer for point-of-care testing

OBJECTIVES

Some studies have shown that a rapid feedback of HbA1c results is helpful for controlling plasma glucose levels. Point-of-care (POC) instruments that are fast, portable, and easy to use are suitable for rapid determination of HbA1c levels. Here, we evaluated the analytical performance of a newly developed POC HbA1c analyzer, SD A1cCare (SD Biosensor, Inc.).

DESIGN AND METHODS

The precision, linearity, and correlation with the Variant II Turbo instrument (Bio-Rad Laboratories, Inc.) were evaluated according to CLSI guidelines for SD A1cCare. All tests were performed according to the manufacturer instructions, and statistical analyses, including linear regression and Passing-Bablok regression, were performed. Bias from the IFCC reference targets was also evaluated with 12 duplicate specimens (n=24 in total).

RESULTS

The coefficients of variation based on EP9-A2 protocol were 2.6% in SI unit and 1.8% in NGSP unit. The calibration curve was linear, with R(2)=0.9911 in the range of 23.5 to 125.1 mmol/mol in SI units (4.3% to 13.6% in NGSP units). The results of the SD A1cCare correlated with those of the Variant II Turbo (r=0.986). Deviations from IFCC targets at 30, 60, and 90 mmol/mol IFCC levels were -1.95, -1.85, and -1.74 mmol/mol, respectively.

CONCLUSIONS

The SD A1cCare analyzer showed excellent precision, linearity, correlation with the Variant II Turbo analyzer, and accuracy with IFCC targets. Therefore, it may be suitable for HbA1c assays in the POC setting and in small laboratories.

Accuracy and clinical utility of a point-of-care HbA1c testing device

BACKGROUND

Point-of-care testing (POCT) is widely used to measure blood glucose levels in people with diabetes, although its use in measuring glycated hemoglobin (HbA1c) levels is less common, perhaps due to perceived performance issues and access to the technology.

METHODS

Forty blood samples were analyzed in duplicate using Bayer's A1CNow + ® Multi-Test A1C system (A1CNow + ) with 3 different reagent lots; HbA1c levels of the samples spanned the clinically relevant range of 4% to 10%. Corresponding samples were sent to a National Glycohemoglobin Standardization Program (NGSP) secondary reference laboratory (University of Missouri Secondary Reference Laboratory #9), which analyzed the samples with a Tosoh Automated Glycohemoglobin Analyzer HLC-723G8 (Tosoh G8; Tosoh Bioscience, Inc).

RESULTS

Glycated hemoglobin levels measured with the A1CNow + aligned with measurements obtained using the laboratory method, with correlation coefficients of 0.985, 0.987, and 0.989 for the 3 lots, respectively. The 95% CIs for the differences between the A1CNow + levels and the mean HbA1c levels were within -0.55% to +0.50% for the 3 reagent lots, which is well within the currently acceptable limits of ±0.75% HbA1c required by the NGSP. Results were further analyzed per the new tighter NGSP performance criteria effective September 1, 2012, requiring that 37 of 40 results be within ±7% (relative bias) of the NGSP reference laboratory measures. All 3 lots met the tighter NGSP criteria.

CONCLUSION

The A1CNow + provides accuracy and precision when performing POCT of HbA1c as an aid in diabetes management. Ongoing improvements in this and other HbA1c POCT devices may lead to a greater global acceptance of the role of POCT of HbA1c in diabetes management.

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. This review describes the biochemistry of HbA1c and the concepts of analytical and biological variation with respect to the measurement of HbA1c. Subsequently, aspects regarding the discovery of HbA1c are described. In addition, an overview is given on the assays methods that are currently available for the measurement of HbA1c. Finally, recommendations for the minimally required analytical performance characteristics of the current HbA1c assays are presented.

The impact of point-of-care A1C testing on provider compliance and A1C levels in a primary setting

PURPOSE

The purpose of the research was to investigate the impact of point-of-care (POC) A1C testing among patients with type 2 diabetes in a primary care setting.

METHODS

This study used a pretest-posttest design with data from patient charts matched for age, sex, race, body mass index, insurance status, and the number of comorbidities. A random sample of charts of patients with type 2 diabetes in the primary care setting was reviewed 6 months and 3 months pre- and post-implementation of the POC A1C testing.

RESULTS

There was a significant difference in the number of A1Cs documented in the medical record pre- versus post-implementation of POC A1C. There was also a significant difference in A1C values pre- versus post-implementation. There was also a difference in the treatment changes pre- versus post-implementation of POC A1C.

CONCLUSION

Point-of-care A1C testing represents an opportunity for improved care of people with diabetes. The significance of this improvement will become more critical as the number of people with type 2 diabetes continues to increase.

Performance evaluation and labeling comprehension of a new blood glucose monitoring system with integrated information management

BACKGROUND

This study evaluated performance and product labeling of CONTOUR® USB, a new blood glucose monitoring system (BGMS) with integrated diabetes management software and a universal serial bus (USB) port, in the hands of untrained lay users and health care professionals (HCPs).

METHOD

Subjects and HCPs tested subject's finger stick capillary blood in parallel using CONTOUR USB meters; deep finger stick blood was tested on a Yellow Springs Instruments (YSI) glucose analyzer for reference. Duplicate results by both subjects and HCPs were obtained to assess system precision. System accuracy was assessed according to International Organization for Standardization (ISO) 15197:2003 guidelines [within ±15 mg/dl of mean YSI results (samples <75 mg/dl) and ±20% (samples ≥75 mg/dl)]. Clinical accuracy was determined by Parkes error grid analysis. Subject labeling comprehension was assessed by HCP ratings of subject proficiency. Key system features and ease-of-use were evaluated by subject questionnaires.

RESULTS

All subjects who completed the study (N = 74) successfully performed blood glucose measurements, connected the meter to a laptop computer, and used key features of the system. The system was accurate; 98.6% (146/148) of subject results and 96.6% (143/148) of HCP results exceeded ISO 15197:2003 criteria. All subject and HCP results were clinically accurate (97.3%; zone A) or associated with benign errors (2.7%; zone B). The majority of subjects rated features of the BGMS as "very good" or "excellent."

CONCLUSIONS

CONTOUR USB exceeded ISO 15197:2003 system performance criteria in the hands of untrained lay users. Subjects understood the product labeling, found the system easy to use, and successfully performed blood glucose testing.

[Capillary HbA1c determination on type 2 diabetes patients in a primary health centre]

OBJECTIVE

To determine the reliability and practicability of the point-of-care- test (POCT) analyzer, Afinion, for capillary HbA1c testing. To assess the benefits of its implementation on the intra-annual follow up of type 2 diabetic patients.

DESIGN

Descriptive cross-sectional study. Analytical validation of the Afinion reader.

SETTING

Primary Health Care (CAP Carmel and Bon Pastor Clinic Laboratory).

PARTICIPANTS

A total of 94 type 2 diabetic patients selected according to their previous HbA1c value.

METHODS

We performed one capillary puncture and one venous extraction on each visit. The capillary sample was assessed in real time on the Afinion in the Primary Health Care Centre and the venous sample was sent to Bon Pastor Clinic Laboratory for assessment on an Afinion analyzer and by a high performance liquid chromatrography (HPLC) reference method. Practicability was assesses by both by the operators of the Afinion and the patients using an 11 question questionnaire. The efficiency in terms of process timings was also evaluated.

RESULTS

Intra-serial coefficient of variation (CV) was lower than 1% and inter-serial lower than 3%. The regression analysis showed: Afinion capillary sample=0.95 Afinion venous+0.21. No systematic or proportional error was detected in the 95% confidence interval (95% CI). The comparison between venous HPLC and Afinion showed: Afinion capillary sample=0.80 HPLC+1.14. A statistically significant difference was shown for these values at the 95% CI. Practicability was valued by users from 7 to 9.2 (professionals) and from 7.7 to 9.2 (patients). Implementation of the Afinion capillary method for intra-annual testing in follow up of diabetic patients could result in the saving of 600-900 professional hours/year.

CONCLUSIONS

Afinion seems to be a good choice for the intra-annual determination of HbA1c when compared to the traditional process due to its accessibility, practicability and efficiency. Professionals should know the limitations of the POCT method in order to consider the validity of the results.

Point-of-care testing for Hb A1c in the management of diabetes: a systematic review and metaanalysis

BACKGROUND

The measurement of hemoglobin A(1c) (Hb A(1c)) is employed in monitoring of patients with diabetes. Use of point-of-care testing (POCT) for Hb A(1c) results at the time of the patient consultation potentially provides an opportunity for greater interaction between patient and caregiver, and more effective care.

OBJECTIVE

To perform a systematic review of current trials to determine whether POCT for Hb A(1c), compared with conventional laboratory testing, improves outcomes for patients with diabetes.

METHODS

Searches were undertaken on 4 electronic databases and bibliographies from, and hand searches of, relevant journal papers. Only randomized controlled trials were included. The primary outcome measures were change in Hb A(1c) and treatment intensification. Metaanalyses were performed on the data obtained.

RESULTS

Seven trials were found. There was a nonsignificant reduction of 0.09% (95% CI -0.21 to 0.02) in the Hb A(1c) in the POCT compared to the standard group. Although data were collected on the change in proportion of patients reaching a target Hb A(1c) of <7.0%, treatment intensification and heterogeneity in the populations studied and how measures were reported precluded pooling of data and metaanalysis. Positive patient satisfaction was also reported in the studies, as well as limited assessments of costs.

CONCLUSIONS

There is an absence of evidence in clinical trial data to date for the effectiveness of POCT for Hb A(1c) in the management of diabetes. In future studies attention to trial design is needed to ensure appropriate selection and stratification of patients, collection of outcome measures, and action taken upon Hb A(1c) results when produced.

Utility of immediate hemoglobin A1c in children with type I diabetes mellitus

OBJECTIVE

Immediate feedback (IFB) of hemoglobin A1c (HbA1c) results to adults with type 1 and 2 diabetes allows more appropriate care decisions at the clinic visit and may improve glycemic control. Our objective is to determine whether IFB of HbA1c results to children with type 1 diabetes will improve patient care and glycemic control.

METHODS

In this prospective randomized controlled trial, children under 18 years of age were randomly assigned to receive HbA1c results during their diabetes clinic visit by point-of-care fingerstick testing (immediate) or several days after by venipuncture and laboratory assessment (conventional). HbA1c levels, therapy changes, and painfulness of testing were recorded at baseline and every follow-up appointment for a year.

RESULTS

The 215 patients studied had similar baseline characteristics including initial HbA1c (7.90 ± 1.24% vs. 7.81 ± 1.13%, p = 0.25). IFB improved HbA1c at 3 months (-0.20 ± 0.66%, p = 0.005) with a return to baseline for the remainder of the study. Subjects receiving conventional feedback had increased HbA1c results at 12 months (+0.27 ± 1.05%, p = 0.048). Less frequent patient-clinician communication between visits was reported with IFB (0.29 ± 0.48 vs. 0.38 ± 0.49 contacts/visit, p = 0.043). Subjects rated fingersticks as less painful than conventional venipuncture (0.30 ± 0.66 vs. 3.9 ± 2.6, p < 0.001).

CONCLUSIONS

IFB of HbA1c is a more acceptable method of HbA1c determination in children with type 1 diabetes mellitus. Although sustained improvements in glycemic control did not result from this intervention alone, IFB testing resulted in more efficient patient-clinician communication and was less painful.

Evaluation of an over-the-counter glycated hemoglobin (A1C) test kit

BACKGROUND

Glycated hemoglobin (A1C) monitoring is an integral component of diabetes management. This study was conducted to evaluate the performance of the A1CNow® SELFCHECK device when used by lay users and health care professionals (HCPs) to measure A1C.

METHODS

Subjects performed two A1CNow SELFCHECK finger-stick self-tests followed by a finger-stick test of the subject's blood by a HCP. The primary endpoint assessed accuracy of the subject and HCP A1CNow SELFCHECK readings. Secondary endpoints included precision, comprehension of instructional material (written material±DVD), and product satisfaction. For accuracy comparison, a venous blood sample was drawn from each subject and tested by laboratory (TOSOH) analysis. Subject comprehension of product instructional material was evaluated via first-time failure (FTF) rate as recorded by the HCP, and subject satisfaction was assessed through written survey.

RESULTS

A total of 110 subjects with (n=93) and without (n=17) diabetes participated. Of 177 subject A1C values, 165 (93.2%) were within the acceptable range of ±13.5% of the laboratory reference value and considered accurate. Regression analysis showed good correlation of subject values to laboratory and HCP results (R2=0.93 for both). The average within-subject coefficient of variation was 4.57% (n=74). The FTF rates with and without instructional DVD were 11.3% (n=56) and 39.6% (n=54), respectively. Subjects with diabetes/prediabetes overwhelmingly indicated that they were "very" to "extremely" likely (93.5%) to discuss their home A1C results with their HCP.

CONCLUSIONS

Lay users found the A1CNow SELFCHECK easy to use, and both lay users and HCPs were able to measure A1C accurately.

Six of eight hemoglobin A1c point-of-care instruments do not meet the general accepted analytical performance criteria

BACKGROUND

Hemoglobin A(1c) (Hb A(1c)) point-of-care (POC) instruments are widely used to provide rapid-turnaround results in diabetic care centers. We investigated the conformance of various Hb A(1c) POC instruments (In2it from Bio-Rad, DCA Vantage from Siemens, Afinion and Nycocard from Axis-Shield, Clover from Infopia, InnovaStar from DiaSys, A1CNow from Bayer, and Quo-Test from Quotient Diagnostics) with generally accepted performance criteria for Hb A(1c).

METHODS

The CLSI protocols EP-10, EP-5, and EP-9 were applied to investigate imprecision, accuracy, and bias. We assessed bias using 3 certified secondary reference measurement procedures and the mean of the 3 reference methods. Assay conformance with the National Glycohemoglobin Standardization Program (NGSP) certification criteria, as calculated from analyses with 2 different reagent lot numbers for each Hb A(1c) method, was also evaluated.

RESULTS

Because of disappointing EP-10 results, 2 of the 8 manufacturers decided not to continue the evaluation. The total CVs from EP-5 evaluations for the different instruments with a low and high Hb A(1c) value were: In2it 4.9% and 3.3%, DCA Vantage 1.8% and 3.7%, Clover 4.0% and 3.5%, InnovaStar 3.2% and 3.9%, Nycocard 4.8% and 5.2%, and Afinion 2.4% and 1.8%. Only the Afinion and the DCA Vantage passed the NGSP criteria with 2 different reagent lot numbers.

CONCLUSIONS

Only the Afinion and the DCA Vantage met the acceptance criteria of having a total CV <3% in the clinically relevant range. The EP-9 results and the calculations of the NGSP certification showed significant differences in analytical performance between different reagent lot numbers for all Hb A(1c) POC instruments.

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. With this in mind, the In2it from Bio-Rad and the DCA Vantage from Siemens were evaluated according to Clinical and Laboratory Standards Institute (CLSI) protocols.

METHODS

The CLSI protocols EP-5 and EP-9 were applied to investigate precision, accuracy, and bias. The bias was compared with three certified secondary reference measurement procedures. Differences between capillary and venous blood were investigated by an end-user group consisting of nurse practitioners at a diabetes care center.

RESULTS

At HbA1c levels of 5.1 and 11.2%, total coefficients of variation (CV) for the In2it were 4.9 and 3.3%, respectively, and for the DCA Vantage were 1.7 to 1.8% and 3.7 to 5.5% depending on the lot number of the cartridges. Method comparisons showed significant lot number-dependent results for the In2it and the DCA Vantage compared with the three reference methods. No overall difference was observed between capillary and venous blood for both methods.

CONCLUSION

Performance results of the In2it and the DCA Vantage showed variable and lot number-dependent results. To maintain the interlaboratory CV of 5% for HbA1c, the Clinical Laboratory Improvement Amendments rules for waived point-of-care instruments should be revised. An obligation for participating in external quality schemes and taking adequate action should be considered for POC instruments that perform poorly.

Hemoglobin A1c: past, present and future

Hemoglobin A1c (HbA1c) has been used for decades to monitor the control of glycemia in diabetes. Although HbA1cis currently undergoing a reassessment, and major developments have been underway in recent years, HbA1c is not recommended at present for diabetes screening or diagnosis. The objective of this review is to summarize the recent developments and to review a potential diagnostic role for HbA1c. Implementation of changes in HbA1c results and units of measurements have been suggested for the purpose of test standardization. These include lower reference ranges (by about 1.5-2 points) and measurement units expressed in percentage (%), as mg/dL (mmol/L) or mmol/mol (or a combination of these units). In diabetes screening and diagnosis, the current diagnostic guidelines use measurement of plasma glucose either fasting or after glucose load. These diagnostic methods have shortcomings warranting a potential diagnostic role for HbA1c. While recent developments in HbA1c methodologies are acknowledged, it is not yet known which changes will be implemented, and how soon. Given the recent literature supporting HbA1c diagnostic abilities, and given the shortcomings of the current guidelines, it is possible that a diagnostic role for HbA1c may be considered in future practice guidelines, globally. Very recently, the first of such recommendations has been proposed by an expert panel, as announced by the US Endocrine Society.

A1cNow InView: a new simple method for office-based glycohemoglobin measurement

BACKGROUND

Glycohemoglobin A1c (HbA1c) is a universally accepted tool for glycemic control. Portable HbA1c devices for use in physicians' offices are desirable because they provide immediate results that physicians can share with their patients. This has been shown to enhance self-management in patients with diabetes. We undertook this study to evaluate the accuracy and precision of a recently introduced device, the A1cNow InView capillary monitor.

METHODS

Previously tested EDTA-preserved whole blood samples from our laboratory pool were preselected based on the results of HbA1c to cover a range from 4 to 13%. HbA1c was then measured using an A1cNow InView capillary monitor. Blinded aliquots of these samples were then sent to a National Glycohemoglobin Standardization Program (NGSP)-certified reference laboratory for comparison. One sample with a laboratory HbA1c result of 9.2% was measured with the InView device nine successive times to assess the device precision. The consistency between the measurement of HbA1c measured by the reference laboratory and the A1cNow InView device was analyzed via linear regression.

RESULTS

Thirty-five samples were tested. The correlation between HbA1c measured by the InView device and the reference laboratory, as well as our own laboratory, was 0.96. The coefficient of variation was 2.71%.

CONCLUSIONS

Results of this study confirm the accuracy and precision of the InView capillary HbA1c monitor. However, the feasibility, reproducibility, and cost-effectiveness of this promising device in the real-life settings of physicians' offices must be verified by prospective clinical studies.