Measurement of glucose content in plasma from capillary blood in diagnosis of diabetes mellitus

Overall, there is good correlation between glucose values obtained from ear capillary blood and those from peripheral venous plasma, but there are considerable individual differences. Results obtained with these two methods are generally not interchangeable and the converted values should not be used in the diagnosis of diabetes mellitus, because of the risk of misclassification. In Denmark this can affect 20-24000 persons. The aim of our study was to investigate whether these differences might be less significant if measurements were taken at the plasma phase of capillary blood and expressed directly as capillary plasma results and if finger capillary blood were used instead of ear capillary blood. The Hitachi 717 instrument was used for measurements of glucose concentrations in venous plasma, the Cobas Mira S in capillary whole blood and the Accu-Chek Inform from Roche in capillary plasma. The conclusions drawn were (1) capillary ear blood glucose concentration correlates well with capillary finger blood concentration and the two sites can be used interchangeably, yielding similar results in the individual patient; (2) sampling variation is almost the same (approx. 0.16 mmol/L) on capillary plasma and capillary whole blood from finger and ear. Sampling variation for venous plasma measured on the Hitachi instrument was 0.13 mmol/L; not significantly better; (3) the analytical imprecision of glucose measurements on capillary plasma (Accu-Chek Inform) and capillary whole blood (haemolysate method) is almost the same (approx. 2.0%). The analytical imprecision of glucose measurements on venous plasma is 0.9% using a laboratory method and almost twice as high using Accu-Chek Inform (2.1%); (4) determination of capillary plasma values in the finger did not improve the correlation with venous plasma values. Even though average values were in better concordance, individual differences did not change. For some persons, both ear- and finger capillary blood measurements deviate significantly from results on venous plasma, such that they cannot be used for diagnosis of diabetes mellitus; (5) the main factor for good correlation is the sampling site. Results obtained on plasma and whole blood from the same puncture correlate well; (6) neither capillary blood nor capillary plasma correlates with the venous plasma method recommended by the American Diabetes Association. It is concluded that physiologic differences in glucose content in capillary- and venous blood prohibit the random use of these two materials in the diagnosis of diabetes.     

New "plasma referenced" POCT glucose monitoring systems--are they suitable for glucose monitoring and diagnosis of diabetes?

BACKGROUND: Results from portable glucose meters should be reported as plasma values as recommended by IFCC. Three new "plasma calibrated" blood glucose meters (Abbott Precision Xcceed, Bayer Ascensia Contour and Roche Accu-Chek Aviva) were compared against laboratory venous plasma glucose measurements to determine their suitability for patient monitoring and diabetes diagnosis. METHODS: 115 capillary blood samples were analyzed on each of the three meters and compared to venous plasma measurements on the Dade Behring RXL analyzer (Hexokinase method). RESULTS: We found a significant positive bias of all meters compared to the laboratory reference method. Deviations of more than 10% were seen in more than a third of all glucose values in all three devices. 13%, 8.7% and 10.4%, respectively, of the values from the Abbott, Bayer and Roche devices fell in zone B or C of the Parkes' error grid. CONCLUSIONS: Neither glucose meter met the ADA or the NACB goals and should therefore not be used as screening tests to diagnose diabetes but are well suitable for patient monitoring.     

Assessment of trueness of glucose measurement instruments with different specimen matrices

BACKGROUND: The trueness of glucose monitors is commonly assessed using whole-blood samples and a clinical analyzer as a comparison method. In this study, the effect of specimen matrix on trueness of one clinical analyzer and one glucose monitor was compared with a gas chromatography-mass spectrometry (GC/MS) reference method, using split-sample comparison with capillary whole blood (CWB), venous whole blood (VWB), and plasma (PL). METHODS: CWB was analyzed by the glucose monitor and the GC/MS reference method. VWB was analyzed by the glucose monitor, clinical analyzer, and the GC/MS method. PL was analyzed by the clinical analyzer and the GC/MS reference method. RESULTS: For the glucose monitor, the bias was 0.4% and -18.2% for CWB and VWB, respectively. The clinical analyzer had a bias of -25.4% for VWB and -12.0% for PL and a proportional bias was detected in both specimens. Using the clinical analyzer as a comparison method, the glucose monitor had a proportional bias of -9.8%. CONCLUSION: The trueness of clinical analyzers can be affected by the specimen matrix that needs to be assessed before they are used as comparison method to assess trueness of glucose monitors.     

Stability of reacted Chemstrip bG

Reacted Chemstrip bG glucose reagent strips have been reported to retain their color changes for up to 7 days. Thus, patients could theoretically measure their blood glucose and mail their reacted test strips to their physicians for reanalysis. To test the stability of reacted Chemstrip bG blood glucose measurements, 268 Chemstrip bG test strips were reacted with blood obtained from 67 insulin-dependent diabetic patients, stored in desiccator vials, and read daily for 5 consecutive days with an Accu-Chek II blood glucose meter. Although Chemstrip bG blood glucose values significantly correlated with initial reference Beckman glucose analyzer glucose determinations for all 5 days, a steady significant decay in blood glucose readings over time was observed, and clinically accurate strip readings declined from 94% to 68%. Because this decay appeared consistent, correction factors were calculated with regression analyses. The correction factor for day 5 Accu-Chek II readings reduced measurement error by 77%. When applied to a different validation sample, this correction factor decreased day 5 error by 73%. Hence, it seems that correction factors may be applied to delayed readings of Chemstrips obtained with Accu-Chek II that would correct for the observed reduction in blood glucose readings. From these results, we conclude that delayed readings of Chemstrip bG test strips with the Accu-Chek II are not sufficiently accurate for clinical decision making or research purposes unless mathematically corrected.     

3款POCT血糖仪的性能分析

目的评价不同便携式血糖仪(POCT)的性能,了解其测定全血葡萄糖(venous blood glucose,VBG)与生化分析仪检测血浆葡萄糖(Venous plasma glucose VPG)结果的差异。方法用新换肝素钠抗凝全血对不同仪器精密度试验、与生化仪比对试验、可报告范围进行测定,结果使用SPSS10.0统计软件进行统计分析。结果 Sure-Step血糖仪、Accu-Chek Active血糖仪、ONE Touch血糖仪批内CV%分别是2.36%~2.54%、1.06%~1.25%、4.20%~4.66%,与生化仪(AU5400)回归方程为Y=1.029 9X+0.1789、Y=0.861 1X+0.527 6、Y=0.926 7X-0.069 7。在医学决定水平处与目标检测系统比较结果差异小于20%。结论不同POCT血糖仪间及其与生化分析仪检测血糖结果的差异显著,POCT可作为血糖检测的筛选,但不能替代生化分析仪血糖测定。     

指尖及手臂部位测定毛细血管血糖和静脉血浆血糖的对比研究

目的研究手臂毛细血管血糖监测的可行性。方法用利舒坦血糖仪对住院糖尿病患者同步测定空腹及餐后2h的手臂毛细血管血糖、指尖毛细血管血糖与同时抽取静脉血用全自动生化仪测定的血浆血糖值作比较。将患者对针刺手臂、指尖的痛觉评分作比较。结果空腹及餐后2h手臂毛细血管血糖与指尖毛细血管血糖及静脉血浆血糖的均值比较,差异无统计学意义;空腹及餐后2h静脉血浆血糖、指尖毛细血管血糖、手臂毛细血管血糖三组相关性良好,r值均在0.950以上,P〈0.001;手臂、指尖的痛觉评分比较,P〈0.001。结论手臂毛细血管血糖监测能精确反应糖尿病患者空腹及餐后2h血糖,且针刺手臂疼痛较轻,患者依从性高。     

Comparison of POCT and central laboratory blood glucose results using arterial, capillary, and venous samples from MICU patients on a tight glycemic protocol

BACKGROUND: Point of care (POC) glucose meters are routinely used to monitor glucose levels for patients on tight glycemic control therapy. We determined if glucose values were different for a POC glucose meter as compared to the main clinical laboratory for medical intensive care unit patients on a tight glycemic protocol and whether the site of blood sampling had a significant impact on glucose values. METHODS: Eighty-four patients (114 paired samples) who were on a tight glycemic protocol in the period November 2005 through August 2006 were enrolled. After simultaneous blood draws, we compared the glucose levels for the glucose meter (arterial/venous/capillary), blood gas (arterial/venous), and central clinical laboratory (serum/plasma from arterial/venous samples). RESULTS: The mean glucose levels of all arterial/venous/fingerstick samples using the glucose meter demonstrated a positive bias of 0.7-0.9 mmol/l (12.6-16.2 mg/dl) (p<0.001) relative to central laboratory venous plasma. There was also a smaller positive (0.1-0.3 mmol/l or 1.8-5.4 mg/dl, p<0.05) bias for arterial/venous blood gas samples and laboratory arterial serum/plasma glucose samples. Using Parkes error grid analysis we were able to show that the bias for arterial or venous POC glucose results would have not impacted clinical care. This was not the case, however, for fingerstick sampling where a high bias could have significantly impacted clinical care. Additionally, in 3 fingerstick samples a severe underestimation (<46% of the central laboratory plasma result) was found. CONCLUSION: Glucose meters using arterial/venous whole blood may be utilized in the MICU; however, due to the increased variability of results we do not recommend the routine use of capillary blood sampling for monitoring glucose levels in the MICU setting.     

Relationships of glucose concentrations in capillary whole blood, venous whole blood and venous plasma

We studied the difference in glucose levels between capillary and venous whole blood during 75-g oral glucose tolerance test (OGTT) in 75 healthy subjects. Capillary and venous whole blood glucose values were measured by HK-G6PD method after deproteinization. The post-loaded glucose levels in capillary blood were significantly higher than those in venous blood, and the mean values of capillary and venous difference at 30, 60, 90, 120 and 180 min were 1.37, 1.40, 1.07, 0.95 and 0.52 mmol/l, respectively, with the maximum difference at 60 min. No correlation was found in the magnitude of the differences in glucose between capillary and venous blood specimens. We determined the inaccuracy of six self-monitoring blood glucose devices relative to the reference method using venous plasma, venous whole blood and capillary whole blood from 31 diabetic patients. The differences of mean values of venous whole blood and capillary whole blood, and venous whole blood and venous plasma, and capillary whole blood and venous plasma were 9.6%, 11.3% and -3.2%, respectively. The range of bias and Sy/x were 0.31-1.06 mmol/l and 0.71-1.07 mmol/l, respectively, compared to the reference method using venous plasma.     

快速毛细血管血糖测定和静脉血浆血糖测定的临床对比研究

目的:评价稳豪型血糖仪的稳定性及其测定指尖毛细血管血糖(CGF)、手臂毛细血管血糖(CGA)与自动生化仪测定静脉血浆血糖(VG)的相关性。方法:选取正常血糖、轻度高血糖、和中高度高血糖的指尖血样用稳豪型血糖仪做批内和批间测定。221例糖尿病或非糖尿病患行常规静脉血浆血糖测试的同时用稳豪型血糖仪测定指尖毛细血管血糖和(或)手臂毛细血管血糖。结果:3种不同浓度的血糖标本测定的批内、批间变异系数均小于5%。VG与CGF、VG与CGA、CGF与CGA3组的空腹血糖及餐后2h血糖相关性良好,r均在0.900以上。血糖浓度<7.0mmol/L时CGA明显高于VG,r=0.757;血糖浓度>11.1mmol/L时,r=0.667,其余各组在不同血糖浓度的相关性均在0.850以上。VG与CGF及VG与CGA的相对差值均在7%以下。结论:稳豪血糖仪有良好的稳定性,CGF及CGA均可比较精确的反应空腹及餐后2h各种血糖浓度的VG并可对VG做初略的估算。     

即时检验血糖仪检测指尖血及静脉全血的血糖结果比对分析

目的探讨指尖毛细血管血及抗凝静脉全血在即时检验(POCT)血糖仪检测结果的可行性。方法分别采取指尖血及静脉血22例,用POCT血糖仪检测血糖,同时在生化分析仪上检测血浆葡萄糖,对两部位血样检测结果与生化分析仪检测结果的偏倚程度进行比对。结果两部位血样POCT血糖仪检测结果与生化分析仪检测结果比对均为负偏倚,偏倚范围最低为-1.5%,最高为-13.9%,均未大于20%;静脉全血血糖偏倚比指尖血血糖偏倚程度高,两偏倚比较差异有统计学意义(P<0.01)。结论无论采用指尖血还是静脉全血,其POCT结果都可以接受,但采用指尖血样其检测结果更接近血浆葡萄糖。     

不同类型标本及仪器对血糖检测结果的影响

目的探讨罗氏血糖仪与全自动生化分析仪检测不同类型标本血糖水平的差异。方法收集2017年2-5月于南京市栖霞区妇幼保健院就诊患者及体检者的末梢血及静脉血标本104例。比较罗氏血糖仪检测的末梢血(末梢血POCT组)、静脉全血(全血POCT组)、静脉血浆(血浆POCT组)、静脉血清(血清POCT组)和全自动生化分析仪检测的静脉血浆(血浆生化仪组)、静脉血清(血清生化仪组)的血糖水平;验证罗氏血糖仪的精密度及线性范围。结果3台罗氏血糖仪的批内CV和批间CV均小于7.5%,符合判定标准。罗氏血糖仪检测的静脉全血血糖水平在1.1~24.4 mmol/L呈线性,R 2>0.95;静脉血清血糖水平在0.6~25.3 mmol/L呈线性,R 2>0.95,均符合线性要求。血糖水平<6 mmol/L的检测结果中,全血POCT组血糖水平低于其余各组(P<0.05);血糖水平为6~10 mmol/L的检测结果中,全血POCT组血糖水平低于血浆POCT组、血清POCT组、血浆生化仪组及血清生化仪组(P<0.05)。各组检测的血糖水平两两之间均具有显著相关性(r>0.99,P<0.05)。结论罗氏血糖仪检测精密度高,具有良好的线性,末梢血、静脉血浆、静脉血清等标本在血糖仪上的检测结果与全自动生化分析仪检测结果具有较好的可比性;罗氏血糖仪检测静脉全血时需进行一定程度的校正以保证结果的准确性。     

试纸目测比色法快速检测末梢血糖

目的探讨目测比色法检测末梢血糖水平的可行性。方法同时采用试纸目测比色法和快速血糖仪检测手指末梢血糖,由被测患者和护士同时读取目测值。结果共检测201例患者,对同一血标本,患者目测血糖值、护士目测血糖值和快速血糖仪所测值之间差异无统计学意义（P〈0．05）,且试纸目测比色法的测量误差与患者年龄无相关性（P〉0．05）。结论试纸目测比色法能准确反映患者的末端血糖值,且不受患者的年龄影响。     

Diagnostics of gestational diabetes: which cutoff-values are valid for capillary whole blood?

National and international recommendations on diagnostics of diabetes are based on laboratory venous plasma examinations. In outpatients, however, most blood sugar determinations in Europe are performed with capillary whole blood and portable blood glucose meters. Our own investigations confirmed the literature findings that capillary blood sugar results cannot be converted to venous plasma values on an individual basis, whereas transformations of the recommended cutoff-values from venous plasma to capillary whole blood are feasible. On the basis of 203 oral glucose tolerance tests (75g) in non-diabetic pregnant women in the 24th-28th week of gestation, the transformation in fasting individuals amounts from 95 mg/dl in venous plasma to 82 mg/dl in capillary whole blood, whereas the 2-hour values of 155 mg/dl are identical. Capillary blood sugar determinations are the only qualified way to determine blood sugar in general practice at the moment, as up to this day no venous blood devices with complete antiglycolytic preservatives are commercially available. Blood sugar determination is one of the most frequently performed and simultaneously least reliable laboratory tests.     

Comparison of several point-of-care testing (POCT) glucometers with an established laboratory procedure for the diagnosis of type 2 diabetes using the discordance rate. A new statistical approach.

The applicability of point-of-care testing (POCT) glucometers for monitoring blood glucose concentrations has been demonstrated. However, their use in diagnosing type 2 diabetes is still debated. Therefore, a new statistical procedure for estimating discordance rates (DRs) was applied in comparing a well-established laboratory method (Ebio) with another laboratory method (Cobas Integra 700) and with several POCT glucometers (Accu-Chek, Accutrend, Elite, HemoCue, Omni) in detecting glucose intolerance states. All procedures led to parallel glucose concentration patterns in capillary blood, venous plasma, and venous blood during oral glucose tolerance tests. However, the mean concentrations differed more or less. The Ebio and Integra results agreed within a maximal deviation of 3%. In blood samples, the HemoCue and Accutrend results were closest to the laboratory procedures (Ebio and Integra) and the highest differences were obtained with the Elite. Comparing whole blood values with those obtained in the aqueous blood compartment (Omni), even greater differences were observed. When all procedures were referred to the same glucose standard, the Ebio, Integra, Accutrend, and Omni results remained almost unchanged, whereas the Elite "moved" toward the Ebio results, and the Accu-Chek results toward the Omni results. Thus, traceability to an aqueous standard was observed with the Ebio, Integra, Accutrend, and Elite in all three sample systems. The Accu-Chek was only traceable in the presence of albumin, and HemoCue was not traceable at all. The clinical relevance of the differences observed between Ebio and POCT glucometers was tested by comparing the relative number of discordant classifications. The highest DRs were observed in the fasting state. They were higher in capillary blood than in the other sample systems. The DRs were found higher with POCT glucometers than with the other established laboratory procedure (Integra). Thus, at least in the fasting state, all POCT glucometers were less reliable than the established laboratory procedures and above the chosen criteria of clinical acceptability (DR < or = 5%). After transforming all glucometer results with a regression function (bias correction), the DRs were less than 5% if compared with the Ebio procedure in all sample systems. In conclusion, the WHO recommendation not to use POCT glucometers for diagnosing type 2 diabetes must be supported. However, after proper recalibration, the tested systems were acceptable. Therefore, manufacturers should reconsider their calibration procedure. Those POCT procedures should be preferred that can be referred to aqueous glucose solutions.     

Oxygen effects on glucose meter measurements with glucose dehydrogenase- and oxidase-based test strips for point-of-care testing

OBJECTIVES: To determine the effects of different oxygen tensions (Po2) on glucose measurements with glucose dehydrogenase (GD)-based and glucose oxidase (GO)-based test strips, to quantitate changes in glucose measurements observed with different Po2 levels, and to discuss the potential risks of oxygen-derived glucose errors in critical care. DESIGN: Venous blood from healthy volunteers was tonometered to create different oxygen tensions simulating patient arterial Po2 levels. Venous blood from diabetic patients was exposed to air to alter oxygen tensions simulating changes in Po2 during sample handling. Whole-blood glucose measurements obtained from these samples with six glucose meters were compared with reference analyzer plasma glucose measurements. Glucose differences were plotted vs. different Po2 levels to identify error trends. Error tolerances were as follows: a) within +/-15 mg/dL of the reference measurement for glucose levels 100 mg/dL. SETTING AND SUBJECTS: Five healthy volunteers in the bench study and 11 diabetic patients in the clinical study. RESULTS: In the bench study, increases in Po2 levels decreased glucose measured with GO-based amperometric test strips, mainly at Po2 levels >100 torr. At nearly constant glucose concentrations, glucose meter systems showed large variations at low (39 torr) vs. high (396 torr) Po2 levels. Glucose measured with GD-based amperometric and GO-based photometric test strips generally were within error tolerances. In the clinical study, 31.6% (Precision PCx), 20.2% (Precision QID), and 23.0% (Glucometer Elite) of glucose measurements with GO-based amperometric test strips, 14.3% (SureStep) of glucose measurements with GO-based photometric test strips, and 4.6% (Accu-Chek Advantage H) and 5.9% (Accu-Chek Comfort Curve) of glucose measurements with GD-based amperometric test strips were out of the error tolerances. CONCLUSIONS: Different oxygen tensions do not significantly affect glucose measured with the GD-based amperometric test strips, and have minimal effect on GO-based photometric test strips. Increases in oxygen tension lowered glucose measured with GO-based amperometric test strips. We recommend that the effects of different oxygen tensions in blood samples on glucose measurements be minimized by using oxygen-independent test strips for point-of-care glucose testing in critically ill and other patients with high or unpredictable blood Po2 levels.     

Preliminary studies of diabetic decompensation assessed with bedside glucose-monitoring techniques

Blood glucose-monitoring techniques originally developed to aid outpatient management of diabetic patients are now being used to facilitate hospital care. However, applications in hyperglycemic patients have been limited because many glucose-oxidase strips and meters respond only to glucose values less than or equal to 400 mg/dl. We asked if prior dilution of blood samples would permit reliable estimations. Ten consecutive decompensated diabetic patients (age 35-73, glucose 506-879, HCO3 12-28) had blood glucose determinations done simultaneously by the hospital laboratory and by Chemstrip bG after dilution of heparinized blood 1:2 in saline. Thirty-one samples were obtained before and during insulin therapy. Correlations with laboratory glucose values were 0.95 with strips read by Accu-Chek meter and 0.90 read visually, both P less than 0.001. Average deviations from laboratory values were 7.9% with Accu-Chek and 12.9% with visual readings. Accu-Chek deviations averaged 9.6% for glucose greater than 700 mg/dl, and 6.9% for glucose greater than 400 mg/dl. Over the first hour of insulin therapy, glucose fell 150 +/- 30 mg/dl by Accu-Chek, comparable to 168 +/- 29 by laboratory measurement; the decrement by visual reading was 107 +/- 32, not significantly different. We conclude that dilution of blood samples with glucose greater than 400 allows reliable estimation of elevated values by home glucose-monitoring techniques. This approach is cost-effective and provides the rapid feedback needed for the management of critically ill patients.     

Accuracy and precision of analyses for total cholesterol as measured with the Reflotron cholesterol method

We compared plasma cholesterol measurements made with the Boehringer Mannheim Reflotron reflectance photometric analyzer in 1298 capillary blood samples with measurements made in venous blood samples collected at the same time and analyzed in four standardized Lipid Research Clinics laboratories. The Reflotron measurements averaged 0.8% to 7.8% lower than the laboratory values. Correlations (r) between the two sets of measurements ranged from 0.92 to 0.96. In some samples, however, the Reflotron values differed from the laboratory values by greater than or equal to 12%; the cholesterol concentrations in these samples tended to be higher than in those for which better agreement was observed. The smaller negative biases were observed when test strips were used that were calibrated with reference to the Centers for Disease Control Reference Method for cholesterol. The agreement between sequential Reflotron values averaged less than or equal to 4.3%. There was an average difference of less than or equal to 1.0% between Reflotron measurements made in each of two sequential capillary blood samples taken from a single finger puncture.     

Can capillary whole blood glucose and venous plasma glucose measurements be used interchangeably in diagnosis of diabetes mellitus?

According to new proposals from the American Diabetes Association (ADA) and WHO, venous peripheral plasma is the preferred system for measuring glucose for diagnosing diabetes mellitus. Owing to the instability of glucose in plasma after blood sampling, strict well-defined and standardized preanalytical conditions are essential to ensure that glucose concentration measured in plasma reflects real blood glucose in the patient. This is in contrast to the capillary whole blood measurements, which are easy to perform and well established. We investigated whether it is possible to perform analysis on capillary whole blood but express the results as plasma glucose values and hence obtain comparable results and the same predictive values for diagnosis in the individual patient? The conclusion of our investigations is that these two systems are not interchangeable and that conversion should not be done for diagnostic purposes where plasma determinations are recommended.     

Effect of adverse storage conditions on performance of glucometer test strips.

OBJECTIVE: A study was conducted to assess the impact of adverse storage environments, i.e., not manufacturer recommended, on the performance of reagent test strips used with a point of care testing (POCT) glucometer to measure whole blood glucose levels. DESIGN/SETTING: Glucose reagent test strips were placed in open, i.e., uncapped, and closed, i.e., capped vials. These vials were those used by the manufacturer to package and store the reagent test strips. One of each type of vial was placed in the manufacturer-recommended storage environment at room temperature and the adverse environments (incubator, direct light to mimic sunlight exposure, humidity, and refrigerated). The Accu-Chek Easy glucometer and reagent test strips as well as Accu-Chek Easy high and low glucose control solutions, manufactured by Roche, were used for this study. MAIN OUTCOME MEASURES: On day-3, day-7, and then once every 7 days, one strip from each vial in each environment was tested with the same glucometer using both a high and a low glucose control. The strip was considered failed for a type of vial and storage environment when either control was out of the reference range on a regular testing day and still out of range when tested the subsequent day. Testing continued up to 50 days. RESULTS: For the tested environments it was found that, overall, test strip stability lasted longer for closed vials than open vials. For open vials in adverse storage conditions, the refrigerator environment offered the longest stability at 35 to 50 days and direct light and humidity offered the shortest periods of stability at 3 to 14 days. CONCLUSIONS: The results of this study support the manufacturer's recommendations to store POCT glucose test strips in their original vial, capped, and at room temperature, though refrigeration may offer an alternative storage environment with acceptable stability. As compliance with testing, quality control, and storage instructions is often an issue with POCT, the manufacturers of these systems for blood glucose measurement should design storage systems that allow the patient to store the glucose meter and the reagent strips in the same location. Manufacturers may also need to consider designing storage systems that are more portable, knowing that patients must take the glucose meters and test strips with them when they travel. Roche's Accu-Chek Compact system is an example of such a design. The glucose test strips are incorporated into a drum that is stored in the Accu-Chek meter itself. When a patient performs a fingerstick blood glucose measurement, the drum advances to move a test strip outside the meter. When the test is complete, the test strip is ejected for disposal. Future studies to clarify the effect of adverse storage conditions, particularly refrigeration, on the integrity of POCT test systems and reagent strips is warranted with currently marketed brands.     

床旁检测血糖和HbAlc的准确性及其应用价值

目的评价床旁检测（POCT）血糖和糖化血红蛋白（HbAlc）的准确性及其应用价值。方法对88例疑似糖尿病者行POCT方法测定HbAlc和实验室方法测定血浆血糖及HbAlc。将POCT方法测定毛细血管血糖及HbAlc的结果与相应静脉血的实验室测定结果作比较，评估POCT与实验室方法检测血糖和HbAlc的相关系数、平均偏差和一致性限度（LOA）等，进行横断面研究。结果两种方法测定值的相关系数为：血糖r=0．98，HbAlc r=0．95。血糖的平均偏差为0．36mmol／L（95％CI：0．13～0．62，LOA：-2．07～2．79mmol／L；P=0．007），HbAlc的平均偏差为0．02％（95％CI：-0．07％～0．09％；LOA：-0．66％～0．68％；P=0．95）。结论POCT检测HbAlc的结果准确可靠，方便实用，适于社区居民现场检测，以监测DM的疗效；而POCT检测血糖的结果尚需通过实验室血糖检测进行定期校正，不能直接用于DM诊断。