Cost-effectiveness analysis for HbA1c test intervals to screen patients with type 2 diabetes based on risk stratification.

BACKGROUND: The best HbA1c test interval strategy for detecting new type 2 diabetes mellitus (T2DM) cases in healthy individuals should be determined with consideration of HbA1c test characteristics, risk stratification towards T2DM and cost effectiveness. METHODS: State transition models were constructed to investigate the optimal screening interval for new cases of T2DM among each age- and BMI-stratified health individuals. Age was stratified into 30-44-, 45-59-, and 60-74-year-old age groups, and BMI was also stratified into underweight, normal, overweight and obesity. In each model, different HbA1c test intervals were evaluated with respect to the incremental cost-effectiveness ratio (ICER) and costs per quality-adjusted life year (QALY). Annual intervals (Japanese current strategy), every 3 years (recommendations in US and UK) and intervals which are tailored to each risk stratification group were compared. All model parameters, including costs for screening and treatment, rates for complications and mortality and utilities, were taken from published studies. The willingness-to-pay threshold in the cost-effectiveness analysis was set to US $50,000/QALY. RESULTS: The HbA1c test interval for detecting T2DM in healthy individuals varies by age and BMI. Three-year intervals were the most cost effective in obesity at all ages-30-44: $15,034/QALY, 45-59: $11,849/QALY, 60-74: $8685/QALY-compared with the other two interval strategies. The three-year interval was also the most cost effective in the 60-74-year-old age groups-underweight: $11,377/QALY, normal: $18,123/QALY, overweight: $12,537/QALY-and in the overweight 45-59-year-old group; $18,918/QALY. In other groups, the screening interval for detecting T2DM was found to be longer than 3 years, as previously reported. Annual screenings were dominated in many groups with low BMI and in younger age groups. Based on the probability distribution of the ICER, results were consistent among any groups. CONCLUSIONS: The three-year screening interval was optimal among elderly at all ages, the obesity at all ages and the overweight in 45-59-year-old group. For those sin the low-BMI and younger age groups, the optimal HbA1c test interval could be longer than 3 years. Annual screening to detect T2DM was not cost effective and should not be applied in any population.

An Evaluation of Two Capillary Sample Collection Kits for Laboratory Measurement of HbA1c.

Background: The COVID-19 pandemic has impacted the conduct of clinic visits. We conducted a study to evaluate two academic laboratories' fingerstick capillary blood collection kits suitable for home use for laboratory measurement of HbA1c. Methods: Four clinical sites recruited 240 participants (aged 4-80 years, HbA1c 5.1%-13.5%). Capillary blood samples were obtained by the participant or parent using collection kits from two laboratories (University of Minnesota Advanced Research and Diagnostic Laboratory (ARDL) and Children's Mercy Hospital Laboratory (CMH)) and mailed under varying shipping conditions by United States Postal Service to the laboratories. Comparisons were made between HbA1c measurements from capillary samples and contemporaneously obtained venous samples. The primary outcome was percentage of capillary HbA1c values within 5% of the corresponding venous values. Results: HbA1c values were within 5% of venous values for 96% of ARDL kit specimens shipped with a cold pack and 98% without a cold pack and 99% and 99%, respectively, for the CMH kits. R2 values were 0.98, 0.99, 0.99, and 0.99, respectively. Results appeared similar across HbA1c levels and for pediatric and adult participants. Usability survey scores were high. Conclusions: Capillary blood collection kits, suitable for home use, from two academic laboratories, were demonstrated to be easy to use and provided results that are comparable with those obtained from venous specimens. Based on these results, there is strong evidence that HbA1c measurements from capillary specimens obtained with these specific kits can be used interchangeably with HbA1c measurements from venous specimens for clinical research and clinical care.

Comparison of a point-of-care analyser for the determination of HbA1c with HPLC method.

AIMS: As the use of Point of Care Testing (POCT) devices for measurement of glycated haemoglobin (HbA1c) increases, it is imperative to determine how their performance compares to laboratory methods. This study compared the performance of the automated Quo-Test POCT device (EKF Diagnostics), which uses boronate fluorescence quenching technology, with a laboratory based High Performance Liquid Chromatography (HPLC) method (Biorad D10) for measurement of HbA1c. METHODS: Whole blood EDTA samples from subjects (n=100) with and without diabetes were assayed using a BioRad D10 and a Quo-Test analyser. Intra-assay variation was determined by measuring six HbA1c samples in triplicate and inter-assay variation was determined by assaying four samples on 4 days. Stability was determined by assaying three samples stored at -20 °C for 14 and 28 days post collection. RESULTS: Median (IQR) HbA1c was 60 (44.0-71.2) mmol/mol (7.6 (6.17-8.66) %) and 62 (45.0-69.0) mmol/mol (7.8 (6.27-8.46) %) for D10 and Quo-Test, respectively, with very good agreement (R2=0.969, P<0.0001). Mean (range) intra- and inter-assay variation was 1.2% (0.0-2.7%) and 1.6% (0.0-2.7%) for the D10 and 3.5% (0.0-6.7%) and 2.7% (0.7-5.1%) for the Quo-Test. Mean change in HbA1c after 28 days storage at -20 °C was -0.7% and +0.3% for D10 and Quo-Test respectively. Compared to the D10, Quo-Test showed 98% agreement for diagnosis of glucose intolerance (IGT and T2DM) and 100% for diagnosis of T2DM. CONCLUSION: Good agreement between the D10 and Quo-Test was seen across a wide HbA1c range. The Quo-Test POCT device provided similar performance to a laboratory based HPLC method.

Patterns of diabetes care in Slovenia, Croatia, Serbia, Bulgaria and Romania : An observational, non-interventional, cross-sectional study.

BACKGROUND: National guidelines for treating type 2 diabetes in the Balkans generally follow European guidelines. The current study was undertaken to estimate the rate of glycated hemoglobin (HbA1c) measurements and level of HbA1c control in diabetic patients treated in regular clinical practice settings in the Balkans and to evaluate if providing HbA1c measurements improves adherence to treatment guidelines. METHODS: This cross-sectional study enrolled type 2 diabetic patients treated by 79 primary care physicians and 102 specialists. The participants were provided with HbA1c measuring devices to measure HbA1c during regular office visits and a physician survey evaluated HbA1c the results feedback. Relevant clinical, demographic, drug treatment and specialist referral data were extracted from patient charts. Descriptive statistics and stepwise multivariate regression analysis were used. RESULTS: Among 1853 patients included (average age 63.5 ± 10.7 years, 51% male) the average diabetes duration was 8.9 ± 7.1 years, 40% of patients had HbA1c measured every 6 months and 34% every 12 months (or less frequently). The rate of 6­month measurement was higher among specialists (43%) vs. primary care physicians (32%, p < 0.01). The average HbA1c was 7.3 ± 1.5 and 35% of patients achieved the target HbA1c level of < 6.5%. Metformin monotherapy was prescribed to 28% of patients and metformin + sulphonylurea to 23%, 55% of patients on metformin monotherapy and 32% of patients on dual therapy metformin + sulphonylurea achieved the target HbA1c < 6.5%. Treatment remained unchanged in 91% and was stepped up in only 7.2% of patients. Physicians were not surprised (in 79% of patients) or were pleasantly surprised (in 11%) by the HbA1c results at the time of visit. Average diabetes duration and patient use of home glucometers were associated with the level of disease control. CONCLUSIONS: The rates of HbA1c measurements remain low in the Balkans, although higher among specialists. Over 60% of patients, mostly treated with traditional oral antidiabetics did not achieve disease control. Providing convenient HbA1c measurement devices was not associated with a marked change in diabetes management. Future research is needed to evaluate the impact of these treatment patterns on long-term outcomes and costs to society.

Evaluation of the new criteria of 2010 for diabetes mellitus: Japan Diabetes Society.

We investigated the characteristics of the new criteria for diabetes mellitus (DM) issued by the Japan Diabetes Society in 2010, which include HbA1C measurement, and differences between 1999 criteria, in order to indicate clinical caution points. If a person with fasting plasma glucose (FPG) ≥126 mg/dl or an oral glucose tolerance test (OGTT) 2-h value ≥200 and HbA1C ≥6.5 % is determined as having DM, the disease can be detected at a rate of ≥70 % in persons <60 years and at no more than 40-50 % in elderly persons. In longitudinal examination, we observed that individuals with DM with FPG ≥126 mg/dl and HbA1C ≥6.5 % obtained the same determination over time at a rate of nearly 90 %. The percentage of persons whose result shifted from normal type to DM was 3- to 4-fold lower than that of persons whose result shifted from normal type to diabetic type. Based on these results, measurement of FPG and HbA1C at the same time may be extremely effective in identifying DM, although we should pay attention to a higher likelihood that mild glucose metabolism disorders will be overlooked.

Comparison of IFCC-calibrated HbA(1c) from laboratory and point of care testing systems.

OBJECTIVE: WHO, IDF and ADA recommend HbA(1c) ≥6.5% (48 mmol/mol) for diagnosis of diabetes with pre-diabetes 6.0% (42 mmol/mol) [WHO] or 5.7% (39 mmol/mol) [ADA] to 6.4% (47 mmol/mol). We have compared HbA(1c) from several methods for research relating glycaemic markers. RESEARCH DESIGN AND METHODS: HbA1c was measured in EDTA blood from 128 patients with diabetes on IE HPLC analysers (Bio-Rad Variant II NU, Menarini HA8160 and Tosoh G8), point of care systems, POCT, (A1cNow+ disposable cartridges and DCA 2000(®)+ analyser), affinity chromatography (Primus Ultra2) and the IFCC secondary reference method (Menarini HA8160 calibrated using IFCC SRM protocol). RESULTS: Median (IQ range) on IFCC SRM was 7.5% (6.8-8.4) (58(51-68) mmol/mol) HbA(1c) with minimum 5.3%(34 mmol/mol)/maximum 11.9%(107 mmol/mol). There were positive offsets between IFCC SRM and Bio-Rad Variant II NU, mean difference (1SD), +0.33%(0.17) (+3.6(1.9) mmol/mol), r(2)=0.984, p<0.001 and Tosoh G8, +0.22%(0.20) (2.4(2.2) mmol/mol), r(2)=0.976, p<0.001 with a very small negative difference -0.04%(0.11) (-0.4(1.2) mmol/mol), r(2)=0.992, p<0.001 for Menarini HA8160. POCT methods were less precise with negative offsets for DCA 2000(®)+ analyser -0.13%(0.28) (-1.4(3.1) mmol/mol), r(2)=0.955, p<0.001 and A1cNow+ cartridges -0.70%(0.67) (-7.7(7.3) mmol/mol), r(2)=0.699, p<0.001 (n=113). Positive biases for Tosoh and Bio-Rad (compared with IFCC SRM) have been eliminated by subsequent revision of calibration. CONCLUSIONS: Small differences observed between IFCC-calibrated and NGSP certified methods across a wide HbA(1c) range were confirmed by quality control and external quality assurance. As these offsets affect estimates of diabetes prevalence, the analyser (and calibrator) employed should be considered when evaluating diagnostic data.