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Glucometer Errors

Glucose Meter Accuracy: Fda's New Dual Call For Tighter Standards

Glucose Meter Accuracy: Fda's New Dual Call For Tighter Standards

Our patient community has been up in arms for quite some time about glucose meter accuracy, or rather lack thereof. Fortunately, the patient-initiated StripSafely campaign seems to have struck a chord, and the FDA has recently -- at long last -- issued new "draft guidance" on accuracy standards. What surprised a lot of people, though, is how FDA chose to split their recommendations into two categories: one set of requirements for meters purchased over-the-c ounter and used by patients in everyday life, and another for meters used in clinical settings by healthcare professionals. And guess which is required to be more accurate? You guessed it: +/-15% for home-use meters and a tighter +/-10% for clinical meters. On top of that, the new guidance is only aimed at NEW products getting ready to undergo FDA evaluation for the first time; it doesn't address the accuracy of meters already on the market -- which disappointed many of us calling for better "post-market surveillance" of meters that may be doing a crap job after some years of use. Also, the new guidance is "non-binding" for manufacturers, so not mandatory. Huh? Last week, the FDA hosted a teleconference led by Courtney Lias, Director of CDRH/Division of Chemistry and Toxicology, to address these concerns with patient advocates, physicians and interested members of the media. The main point Lias seemed to want to convey is that the FDA is trying to be practical here, by issuing what they believe to be reasonable and achievable guidelines. "The technology isn't currently sufficient for manufacturers to meet +/-10% accuracy at the huge volume of lay use, but for the smaller volume of tests done in clinical settings, they can... In an ideal world, everyone would have a meter that's within 5-10% of the accuracy reference, Continue reading >>

Factors Affecting Blood Glucose Monitoring: Sources Of Errors In Measurement

Factors Affecting Blood Glucose Monitoring: Sources Of Errors In Measurement

Go to: Measuring Accuracy Accuracy of a blood glucose meter is a measure of how closely the average of a series of values reflects the reference value. As seen in Figure 1 (left), the average of a series of values can be perfectly accurate, although none of the individual values is representative of the reference. Precision describes the reproducibility of a series of values, independent of the closeness of any of the values to the reference. Again, as seen in Figure 1 (center), a series of values can be highly precise, although none of the individual values is representative of the reference. Only when a series of values is both accurate and precise (Figure 1, right) do the individual values actually reflect the reference value. Figure 2 shows these same definitions applied to SMBG. The green line defines perfect accuracy. As seen on the left, a series of measurements, half of which are high by 100 mg/dl and half low by 100 mg/dl, would be considered perfectly accurate as a set since the high values and the low values would average to the true value. Conversely, as seen in the center of Figure 2, a series of measurements, each of which is high by 100 mg/dl, would be considered perfectly precise although biased. As seen on the right in Figure 2, only when a series of values are both accurate and precise do all of the values fall exactly on the green line of accuracy. The best single measure of both accuracy and precision is the mean absolute relative error (MARE) (also called mean absolute relative deviation or MARD and mean absolute error or MAE). Mean absolute relative error is calculated by taking the average for the set of individual absolute errors relative to its reference value (Figure 3). So, for example, with a reference value of 100 mg/dl, measured values of b Continue reading >>

Blood Glucose Meter Accuracy Comparison (chart)

Blood Glucose Meter Accuracy Comparison (chart)

How accurate is your blood glucose meter? A major study found that almost half of meters do not meet the minimum required standards: For blood sugars over 75 mg (4.2 mmol): Accurate within 20%. For example, if your blood sugar is 200 mg (11 mmol), the meter must read between 160 (8.8 mmol) and 240 (13.3 mmol) at least 95% of the time. For blood sugars under 75 mg (4.2 mmol): Accurate within 15 mg. For example, if your blood sugar is 60 mg (3.3 mmol), the meter must read between 45 (2.5 mmol) and 75 (4.2 mmol) at least 95% of the time. There is a new proposal that would require all results to be within 15%. But how do you know if your meter is meeting this standard? Today, there is no systematic verification of meter accuracy after it gets approved for sale. And as you will see below, many meters are sub-standard. This puts people relying on these tools in unnecessary danger. If you’re going to take a shot of insulin, a number that’s 15% off is a really big deal. Taking too much insulin can result in severe low blood sugars, hospitalization and even death. Comparison of Meter Accuracy The chart below is from System Accuracy Evaluation of 43 Blood Glucose Monitoring Systems for Self-Monitoring of Blood Glucose according to DIN EN ISO 15197 by Dr. Guido Freckmann and others published in Journal of Diabetes Science and Technology, Volume 6, Issue 5, September 2012. Between 2009 and 2011, over a hundred people were recruited to test each of the meters listed below. The test strips were taken from at least seven different vials of one manufacturing lot. Over at least ten days, the patients tested their blood sugar with the meter and then a second sample was taken for analysis in a lab. Before using this data, it is important to know the limitations: The study only looked Continue reading >>

Blood Glucose Monitors: What Factors Affect Accuracy?

Blood Glucose Monitors: What Factors Affect Accuracy?

Sometimes my blood glucose monitor seems to give incorrect readings. What can I do to make sure the measurement is accurate? Answers from M. Regina Castro, M.D. When used correctly, blood glucose monitors — small devices that measure and display your blood sugar level — are usually accurate. But occasionally they may be incorrect. Consider these factors that affect meter accuracy and the steps to resolve or prevent the problem: Factors that affect accuracy Solutions Test strip problems Throw out damaged or outdated test strips. Store strips in their sealed container; keep them away from heat, moisture and humidity. Be sure the strips are meant for your specific glucose meter. Extreme temperatures Keep your glucose meter and test strips at room temperature. Alcohol, dirt or other substances on your skin Wash and dry your hands and the testing site thoroughly before pricking your skin. Improper coding Some meters must be coded to each container of test strips. Be sure the code number in the device matches the code number on the test strip container. Monitor problems Fully insert the test strip into the monitor. Replace the monitor batteries as needed. Not enough blood applied to the test strip Touch a generous drop of blood to the test strip. Don't add more blood to the test strip after the first drop is applied. Testing site location If you're using a site other than your fingertip and you think the reading is wrong, test again using blood from a fingertip. Blood samples from alternate sites aren't as accurate as fingertip samples when your blood sugar level is rising or falling quickly. The amount of red blood cells in your blood If you are dehydrated or your red blood cell count is low (anemia), your test results may be less accurate. Blood glucose monitor quality Continue reading >>

Glucometer Errors

Glucometer Errors

Study shows venous blood tests artificially high on capillary glucometers. Did you know that it matters where you get the blood sample from when youre usinga glucometer? If you did, congratulations. You understand more than I did about glucometers before I read this study that showed venous blood tests as much as 17.42 mg/Dl higher on capillary glucometers than capillary blood. If your agency is using standard, over-the-counter capillary glucometers, these are specifically calibrated to give accurate readings on capillary blood. The kind of blood your finger oozes when you poke it with a lancet. Not the direct venous blood that you might get off your IV needle or directly from the end of the IV catheter. Does this mean that you should stop using the IV site, or needle, or little drops of blood on your bench seatto test the patients glucose level? Not necessarily. Venous blood will still give you an accurate ballpark estimate of the patients glucose level. Just be aware that if youre looking for a dead-on accurate blood glucose level on your diabetic or altered mentation patient, you need to do a finger stick. And know that a venous blood sample reading will most likely be an artificially high number. Continue reading >>

Help Your Patients Get Accurate Blood Glucose Readings

Help Your Patients Get Accurate Blood Glucose Readings

With over 20 million patients with diabetes in the United States, many of these patients must rely on monitoring their blood glucose at home to ensure that they are staying within their target goals. Unfortunately, too often patients receive inaccurate glucose readings due to a variety of factors. This article will focus on some common causes of inaccuracies with glucometer results, including environmental factors, hematocrit issues, sampling errors, and testing interferences. Environmental Factors Test strips that are stored in vials, as opposed to strips that are individually wrapped in foil, are susceptible to the effects of oxygen and moisture. Several small studies that reviewed the effects of glucose test strips left open in their vial for times ranging from 2 to 18 hours showed variances in blood sugar results from 9% higher to 60% lower than the actual results. A study in Diabetes by Lilavivat et al, in 2002, reported varying results for one patient between 94 and 307 mg/dL over the course of a few weeks. It was determined that the patient's test strips had been exposed to moisture. These factors must not be overlooked, given that many patients will keep their testing supplies in a bathroom or kitchen environment. Make sure that your patients understand to always keep their test strip vial closed when not in use. Heat exposure can also be a factor for vials of test strips as well as the individually foil-wrapped test strips. This is particularly a consideration for patients who use mail order as well as patients living in warmer, humid climates who may not use a source of air conditioning in their home. Counsel patients to make sure that they do not leave their test strips in the mailing box for extended periods of time if they order by mail and to use insulated Continue reading >>

10 Common Problems You May Face When Using A Glucose Meter At Home

10 Common Problems You May Face When Using A Glucose Meter At Home

We have previously discussed what are common causes of test strip errors. In this article, we will address tips on how to deal with common problems when using a glucose meter at home. Glucose monitoring at home plays a major role in diabetes management. It is evident that quality of life has improved for those who properly monitor their glucose levels at home. Home monitoring of glucose levels comes with some challenges, one of which is the use of the glucose meter. Even with the most expensive and well-designed meters you may find yourself trouble shooting from time to time. 10 Most Common Problems with the Use of Glucose Meters Test strip is damaged or used. Repeat the test with a new test strip. Glucose test strips are for single use – do NOT reuse strips! Test Strip is expired. Repeat the test with a new strip. To avoid getting erroneous results check the expiration on the test strip vial. Do not use short-dated test strips. Test strip is not fully inserted in the meter. Always check the test strip to make sure it is fully inserted in the meter. Test strip is moved. Do not move the test strips after it’s fully inserted in the meter. Test strip or control solution is kept at temperature above or below the operating range. Be sure to store your test strips and control solution at proper temperatures according to the instructions provided by the manufacturer. Not sufficient amount of blood is applied to test strip. Check the instructions for sufficient amount of blood sample then repeat the test with a new sample and test strip. Sample site is contaminated. Always clean and dry the sample site before lancing and sampling. Low Battery! Change the batteries and redo the test. Alternative sites – sample sites other than fingertips. Be aware that the readings of samp Continue reading >>

8 Common Mistakes That Affect The Accuracy Of Blood Glucose Test Reading

8 Common Mistakes That Affect The Accuracy Of Blood Glucose Test Reading

Most blood glucose testing meters sold in the market are precise and accurate since they have been heavily tested and checked by the experts in labs before approval for sale. In most circumstances, the accuracy of test reading are affected by mistakes made by consumers or users whom are doing the test. Here are 8 common mistakes that we have observed. 1. Contaminated meter or testing strip Meters that have not been properly cleaned and contaminated with old blood may cause false high or low readings. Testing strips that have been used should be thrown away after each use. In addition, storage of strips should be secured at all times with the cap tightened. 2. Meter or testing strip not within the normal room temperature Meters or testing strips that are exposed to either too high or too low room temperature will cause false reading. Be reminded that you should always keep all your blood testing equipments in a dry and normal environment. Avoid them from the reach of your children if possible. 3. Expired or used testing strip Strips that have been outdated or used in previous test should be kept away whenever a new test is to be performed as they may affect the result too. 4. Uncalibrated meters You should calibrate your meter for it to have a correct code matching the test strips you are going to use. Always remember to perform your calibration before any test to ensure reading accuracy. As some meters calibrate automatically, you may like to put this into consideration when choosing your blood glucose meter. 5. Too little or large drop of blood Too small a drop of patient blood for testing may also give a false low reading. Patients should remain calm and relaxed at all times. In addition, there should not be an over-squeezed amount of blood too. 6. Strip not fully ins Continue reading >>

Performa Error Screens | Accu-chek

Performa Error Screens | Accu-chek

Battery is dead. Insert new battery. Insert one 3-volt lithium battery (coin cell type CR2032) Display is damaged. Contact Accu-Chek Enquiry Line on 1800 251 816 Meter is defective. Contact Accu-Chek Enquiry Line on 1800 251 816 Extreme temperatures. Move the meter to a more temperate area. The meter is in set-up mode, waiting for you to change or confirm settings. The meter is ready for you to insert a test strip. The meter is ready for a drop of blood or control solution. Your meter measures blood glucose within a defined range (0.633.3 mmol/L). The display may indicate that your blood glucose is above that of the measuring range of the system (33.3 mmol/L). Immediately repeat the test. If your test result matches how you feel, contact your healthcare professional immediately. If this does not match how you feel, contact the Accu-Chek Enquiry Line on 1800 251 816. Your meter measures blood glucose within a defined range (0.633.3 mmol/L). The display may indicate that your blood glucose is lower than the measuring range of the system (0.6 mmol/L). Immediately repeat the test. If your test result matches how you feel, contact your healthcare professional immediately. If this does not match how you feel, contact the Accu-Chek Enquiry Line on 1800 251 816. The test strip may be damaged or not properly inserted. Remove and reinsert the test strip, or replace it if damaged. Your blood glucose may be extremely high or a meter or a test strip error has occurred. If your test result matches how you feel, contact your healthcare professional immediately. If your test result does not match how you feel, repeat the blood glucose test. If the E-3 code still appears for your blood glucose test, your blood glucose result may be extremely high and above the systems reading range. Co Continue reading >>

What Causes A Test Strip Error On My Meter?

What Causes A Test Strip Error On My Meter?

Glucose meters display error messages when there are problems with test strips, problems with the glucose meter, or when your glucose level is higher or lower than normal. One of the common errors is the test strip error. This error is often an easy fix. However, it’s important to understand the test strip error so you can prevent it from happening again in the future. Every time a test strip error occurs you will need to repeat the test with a new test strip. This often results in use of a few test strips which can become costly over time. Test Strip Error First and foremost, make sure you are using the right test strip with your meter. Using test strips that are incompatible with your meter often causes an error. If you’re not sure which test strips to use with your meter, contact the manufacturer. Here are a few common test strip errors: High or Low Operating Temperature: your glucose meter may display a test strip error when the it detects that the temperature is above or below the operating range. Do not perform a test until the meter and test strips reach a temperature within the operating range of your glucose monitoring system. Used, Damaged, or Expired Test Strip: glucose test strips are for single use. Do not use expired, short-dated, used, or damaged test strips. In this case, repeat the test with a new strip. Always read the safety instructions provided in the test strip box. Keep your strips in their original packages and away from heat, humidity and sunlight. Do not leave them open to air because that will make the strip unusable. When you remove a test strip for use, place a clean cloth underneath it in case you drop it; this way it will still be clean and usable. Always dispose used test strips and never use them again. You may also get a test strip Continue reading >>

Everything You Need To Know About Diabetes Test Strips

Everything You Need To Know About Diabetes Test Strips

Update: A lot of our readers ask us where can they find the best deals for test strips. We personally recommend Amazon. You can check the list of selections they offer by clicking here. Blood glucose test strips play a crucial role in helping you to monitor your daily blood glucose level and giving your doctor the data to adjust your medication to control your diabetes symptoms. Without the help from these little disposable strips, life with diabetes can become even more chaotic than ever. But what exactly are these thin little plastic slip and why are they so expensive? Are there any alternative method I can use? Where can I get the best deal on these test strips? This article will answer many of your questions and concerns regarding these blood glucose test strips: Table of Contents History on Glucose Test Strips How Does the Test Strips Work Why Are the Strips So Expensive? And Why the Price Discrepancy? Why Must Diabetic Patients Use Glucometer and Test Strip? How Often Should You Administer A Blood Glucose Test? How to Find Out if Your Glucose Monitor is Accurate? How Accurate Are the Test Strips? How to Find Out if Your Glucose Monitor is Accurate? What is a Urine Glucose Test? Can’t I Use This Procedure Instead? Expiration of Test Strips Medicare Plan B Coverage for Glucose Test Strips Where to Get the Best Deal on Test Strips? Ways to Save of Test Strips How to Avoid Counterfeit Blood Glucose Test Strips Can You Reuse Test Strips? Can You Make Your Own Test Strip? 4 Most Affordable Meters How to Pick the Right Glucometer? How to Dispose Used Test Strips, Lancets, and Needles? What to Do with All These Test Strip Containers? Selling Your Glucose Test Strips A Good Idea? Odd Way to Earn Some Money Back Questions? History on Glucose Test Strips The first glucomet Continue reading >>

Glucose Meter

Glucose Meter

Four generations of blood glucose meter, c. 1993–2005. Sample sizes vary from 30 to 0.3 μl. Test times vary from 5 seconds to 2 minutes (modern meters typically provide results in 5 seconds). A glucose meter is a medical device for determining the approximate concentration of glucose in the blood. It can also be a strip of glucose paper dipped into a substance and measured to the glucose chart. It is a key element of home blood glucose monitoring (HBGM) by people with diabetes mellitus or hypoglycemia. A small drop of blood, obtained by pricking the skin with a lancet, is placed on a disposable test strip that the meter reads and uses to calculate the blood glucose level. The meter then displays the level in units of mg/dl or mmol/l. Since approximately 1980, a primary goal of the management of type 1 diabetes and type 2 diabetes mellitus has been achieving closer-to-normal levels of glucose in the blood for as much of the time as possible, guided by HBGM several times a day. The benefits include a reduction in the occurrence rate and severity of long-term complications from hyperglycemia as well as a reduction in the short-term, potentially life-threatening complications of hypoglycemia. History[edit] Leland Clark presented his first paper about the oxygen electrode, later named the Clark electrode, on 15 April 1956, at a meeting of the American Society for Artificial Organs during the annual meetings of the Federated Societies for Experimental Biology.[1][2] In 1962, Clark and Ann Lyons from the Cincinnati Children’s Hospital developed the first glucose enzyme electrode. This biosensor was based on a thin layer of glucose oxidase (GOx) on an oxygen electrode. Thus, the readout was the amount of oxygen consumed by GOx during the enzymatic reaction with the substra Continue reading >>

Checking Blood Sugar: Blood Glucose Meter Accuracy

Checking Blood Sugar: Blood Glucose Meter Accuracy

If handheld blood glucose meters were always as accurate checking blood sugar levels as the much bigger (25 pounds), much more expensive ($10,000) analyzers that hospitals and labs use, then hospitals and labs would use the small, personal blood sugar meters. Find out more about how meters get to market, what to look for when choosing your next meter, and how to calculate the performance results of the meter you have now. How meters get to market To get clearance to market a new meter, a manufacturer needs to submit data to the U.S. Food and Drug Administration (FDA) that shows the new blood glucose monitoring system (meter plus test strips) is as safe to use and effective as other devices on the market that have FDA clearance. Many meter companies cite criteria published by the International Organization for Standardization (ISO), a network of the national standards institutes of 162 countries, based in Switzerland. The standard for blood glucose meters is ISO 15197, published in 2003. It is an FDA-recognized standard. It includes instructions for manufacturers on how tests of accuracy are to be run and what counts as a passing grade. Companies don't have to go by the ISO standard. According to the FDA, "Conformance with recognized consensus standards is strictly voluntary for a medical device manufacturer. A manufacturer may choose to conform to applicable recognized standards or may choose to address relevant issues in another manner." So if a manufacturer isn't using the ISO standard, it still has to make a case to the FDA that the device and strips are as safe to use and effective as others on the market. How is accuracy tested? Accuracy means how close the meter's results are to the results from a big, expensive, carefully calibrated lab analyzer. ISO requires man Continue reading >>

Reporting Problems With Your Blood Glucose Meter

Reporting Problems With Your Blood Glucose Meter

Reporting Problems With Your Blood Glucose Meter Occasional problems can occur with blood glucose meters . This guide shows which problems need to be reported. When reporting a problem with your blood glucose meter, contact the manufacturer as soon as you are able. Blood glucose meter manufacturers have a legal responsibility to follow any reports of problems with their glucometers. The following problems are example which should be reported to the blood glucose meters manufacturer. Display issues such as failure to display part or all of a result. If failure to display is the result of damage, for example being trodden on, your meter manufacturer may be able to help replace your meter. Performance problems include falsely high or low results or incorrect calibration. These errors could be related to the meter or the test strips. The meter company will be able to help discover which. Some blood glucose meters require a calibration code to be entered which can lead to mistakes and errors. A number of meters these days feature no coding technology to reduce mistakes occurring. Blood glucose meters should come with intelligible user guides to help you to use your meter correctly. If the meter comes without the user guide, or the wrong user guide, this should be reported. Problems arising from faulty manufacture might include failure to switch on or switching to displaying the wrong units. Error codes may typically appear for reasons including: Blood test sample smeared or not large enough Temperature of the strip is too warm or cold Meter error codes should need to be reported as such. However, if they are persistent or seem to be wrong or invalid, this will need to be reported to manufacturer. Continue reading >>

Capillary Glucose Meter Accuracy And Sources Of Error In The Ambulatory Setting

Capillary Glucose Meter Accuracy And Sources Of Error In The Ambulatory Setting

Glucose results derived from hand-held meters are used by patients and their health care team to make therapeutic decisions such as insulin dosing. Incorrect glucose values may result in both acute and also long-term therapeutic consequences. It is therefore essential that results are as accurate and precise as possible. Meter technology has shown incremental improvements since the introduction of the first commercially available hand-held meters in 1970s, including improvements in ease of use, technical performance and affordability.1-3Capillary glucose testing is an international multi-billion dollar industry.2 In New Zealand reimbursement of test strips for the 12 months to June 2009 was $19 million, accounting for 40% of PHARMAC’s entire diabetes ‘spend’. The number of meters available has expanded, both in New Zealand as well as internationally.1,2 Currently in New Zealand, six different meters are available for use with PHARMAC funded strips (see Table 1). It is therefore timely to describe current meter technology from a clinical perspective, highlighting some of the limits of meter performance. This review focuses on technical issues that impact on clinical interpretation of meter results in the ambulatory setting. It does not aim to be a comprehensive technical discussion. Although there are additional meter systems available in New Zealand with unsubsidised strips such as the Glucocard, which is used in many hospital inpatient settings, the focus of this review is meters with subsidised strips. Recent developments in meter technology have improved this testing system’s ease of use and analytical robustness.1-3 Test strips now require 8μL or less of blood (see Table 1). Using a low blood volume system has the following advantages: It allows most patien Continue reading >>

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