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Blood Sugar Meter Errors

Why Glucose Meter Accuracy Needs To Be Improved

Why Glucose Meter Accuracy Needs To Be Improved

Why Glucose Meter Accuracy Needs To Be Improved Thu, 02/23/2012 - 14:37 -- John Walsh PA CDE Due to complaints about glucose meter inaccuracy, the Food and Drug Administration (FDA) is currently developing a new standard for glucose meter accuracy. This update is driven by ongoing improvements in meter accuracy, the need for better accuracy with today's pumps, bolus calculators , and continuous glucose monitors, reports of hospital and out-patient deaths, consumer complaints, and research studies showing that several approved glucose meters failed to meet FDA or International Standards Organization (ISO) standards in post-approval testing.1-3 Most users assume their glucose meter is accurate and use it to make therapeutic decisions. Yet significant differences in accuracy exist between and within meter brands that are often unrecognized by clinicians and people with diabetes. For example, brand-to-brand variations may be discovered when a health insurer selects a lower cost meter as the preferred brand and user perform simultaneous glucose tests on the old and new meters. The greatest danger that the FDA is concerned about occurs when an erroneous reading on a glucose meter causes severe hypoglycemia or death after an excessive dose of insulin in a hospital or home. Figure 1. Blood GM accuracy and precision. Accuracy measures how close the average of a series of meter values is to an average of the reference values, regardless of the error in individual values. Precision shows consistency of readings or how closely a series of meter values agree with each other, regardless of how close they are to the reference, often measured as coefficient of variation. Accuracy and precision are optimal meter values, often measured as mean absolute relative error. Figure 2. Blood GM 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 >>

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 >>

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 >>

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 >>

Checking Blood Sugar: Blood Glucose Meter Accuracy

Checking Blood Sugar: Blood Glucose Meter Accuracy

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 manufacturers to test their meters with blood samples from at least 100 people, preferably at a diabetes clinic or hospital, and each sample must be tested with two meters as well as the lab analyzer. Blood samples from below 50 mg/dl to above 400 mg/dl must be tested. To get samples that are far outside the healthy range, blood can be altered. For example, glucose can be added to blood to get samples in the 400s. Minimum Acceptable Meter Accuracy The ISO figures, based on device testing, do not guarantee results or protect against common user errors. When glucose range of blood sample is Lower than 75 mg/dl: 95 percent of the results must fall within +/- 15 mg/dl When glucose range of blood sample is 75 mg/dl or Higher: 95 percent of the results must fall with +/- 20 percent Examples of Acceptable Accuracy: If the lab result is 70 mg/dl: The meter reading must be within 55-85 mg/dl If the lab result is 100 mg/dl: The meter reading must be within 80-120 mg/dl If the lab result is 200 mg/dl: The meter reading must be within 160-240 mg/dl Close enough? People talk about good and bad blood glucose results. To people with diabetes (PWDs), the term "good" means within their goal range; "bad" means way outside the range. Diabetes educators say all results are good because they provide information that helps you manage your diabetes. That is assuming the results are accurate. When talking about meter accuracy, a good result is one that prompts you to take a correct action. A bad result is so far off that it leads a person to immediately act on an incorrect decision, such as correcting a false high with too much insulin, Continue reading >>

Operator Error In Diabetes Testing

Operator Error In Diabetes Testing

Saying that operator error is the biggest problem that people who have diabetes have when we check our blood sugar sounds like blaming the victim. But I’m convinced that some mistakes we make when using our meters and test strips and lancets is the reason why testing so often gives us wacky blood sugar numbers. People with diabetes know all about blaming the victim. For years I have argued against the common fallacy that diabetes is a lifestyle disease caused by our weight and sloth. In fact, most of us have diabetes in our genes, as the new science of genetic testing shows. But sometimes – and not always – the victim herself or himself causes the error. That’s what is going on with some of the inaccurate readings that those of us who have diabetes often get from our blood glucose meters. For more than 40 years, people who have diabetes have been lucky to be able to check their blood sugar levels at home and when travelling. We can do it whenever we need to do so. We don’t have to go to a doctor’s office or a hospital or a lab. Consequently, we forgot what a sophisticated testing device we have in our hands. Blood glucose meters are one of very few blood testing devices that the U.S. Food and Drug Administration lets untrained people use. And we are for the most part completely untrained in how to use our meters. Is it then any wonder that we screw up the procedures once in a while? Maybe the most common mistake we make is when we don’t get enough blood on the test strip. After using dozens of different blood glucose meters since a doctor told me almost 20 years ago that I have diabetes, I know from my own experience that when I don’t get quite enough blood on the test strip that the result the meter reports will be off. Usually, it will say that my leve Continue reading >>

Accu-chek Aviva Meter Error Screens | Accu-chek

Accu-chek Aviva Meter Error Screens | Accu-chek

Extreme temperatures. Move the meter to a more temperate area. If you see 3 dashes or hyphens, the meter is not coded or the code key is not inserted. Turn off the meter and make sure the code key is properly inserted. If this does not fix the problem, please contact Accu-Chek Customer Care . A battery icon means the battery power is low. Change the battery soon. Download the owner's booklet now and refer to Chapter 7, "Changing the Batteries." A battery icon means the battery power is low. Change the battery soon. Download the owner's booklet now and refer to Chapter 5, "Changing the Battery." "Set-up" means the meter is in the set-up mode, waiting for you to change or confirm settings. Download the owner's booklet now and refer to Chapter 5, "Using the Set-Up Mode." "Set" means the meter is in set mode, waiting for you to change or confirm settings. Download the owner's booklet now and refer to Chapter 4, "Meter Setup." If you see "code exp," the test strips expire at the end of the current month. Make sure the time and date in the meter are correct. If this does not fix the problem, please contact Accu-Chek Customer Care . If a test strip icon is flashing, the meter is ready for you to insert a test strip. If you see a blood drop and test strip, the meter is ready for a drop of blood or control solution. If you see the letters HI, your blood glucose may be higher than the measuring range of the system. Download the owner's booklet now and refer to Chapter 4, "Unusual Blood Glucose Results." If you see the letters LO, your blood glucose may be lower than the measuring range of the system. Download the owner's booklet now and refer to Chapter 4, "Unusual Blood Glucose Results." A star or asterisk means a marker was assigned to this test result. A star or asterisk mean Continue reading >>

Getting Accurate Blood Glucose Test Results

Getting Accurate Blood Glucose Test Results

For the most part, blood glucose meters—devices that measure and display blood glucose levels—are simple to use and provide readings you can trust. But they aren't perfect and inaccurate readings are possible. Extremely high or low readings that are made in error can have serious consquences. Inaccurate readings happen for a variety of reasons, including human error. But the error can usually be corrected without much effort. Here are some common mistakes users make along with tips to help you improve the reliability of your device and your test results. But first, it's important to note that if you get a reading that seems way off—especially one that doesn't match your symptoms—always perform a re-test. When re-testing, take your time to ensure you are using the strips and the device correctly and repeat the procedure. If you get a similar reading again, call your healthcare professional or the phone number on the back of the meter as malfunctions can occur and product recalls happen periodically. The following factors can impact meter accuracy.If you find you are contributing unintentionally to the problem, take the necessary steps to get the right results: Be sure your meter and hands are clean. It seems like a no-brainer, but a dirty meter can alter your reading. Clean your meter regularly, and before you do a reading, wipe off any noticeable blood, dirt, or grease. It's also vital to perform your test on a clean fingertip. Wash your hands with soap and warm water before extracting a blood sample. Be aware of test strip issues. Make sure your test strips are compatible with your meter. Saving money by purchasing less expensive strips that are not designed to work with your meter is a bad idea. Be sure the strip is inserted correctly into the meter. Test stri Continue reading >>

Bg Meter Accuracy: 10 Meters Put To The Test!

Bg Meter Accuracy: 10 Meters Put To The Test!

These 10 meters varied in age and wear.Some were old, some were new one wasmy own personalmeter that I used to calibrate my CGM and make mission-criticaldecisions each day.All of them passed their respective control solution tests, so its safe to assume that they werein good working order. I tried to match the testing method employed by Chris (author of the original post ) as closely as possible. Eightrounds of testing were performed over the course of 24 hours according to the following procedure: Order of meters was randomized for each round. Tests were performed only when CGM readings were stable (i.e. no insulin on board and CGM showing a slope of ~0 mg/dL/min). I didnt do anything special to stabilize my blood glucose just tested as I went about a normal day. The test strips used for each meter all came from their own unique vials. Before and after completing the eight testing rounds, the meters were checked using their respective control solutions. They all passed the control solution tests. Unlike Chris, I didnt have an alarming spread in my results for any round. The overallbetween-meter variability (% Error, or %CV for you stats folks) was only 6%. In plain English:My treatment decisions wouldnt have varied much at all, regardless of the meter I was using. One unit of rapid-acting insulin brings my BG down by ~80 mg/dL, and I correct whenever Im over 100 mg/dL. Ill usually correct down to 70-110 mg/dL, depending on my plans for the next couplehours (big meal = correct to 70; workout = correct to 110). Iwasrelieved to see that even if I tooka correction bolus for the maximum BG of each round, I still would have been brought down to a desirableblood glucose level. For example, take Round 1. The highest reading I saw was 182 md/dL, and Id take 1 unit for that. Ev 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 >>

Meter Error Or My Error?

Meter Error Or My Error?

I bought a Freestyle lite meter yesterday. After a few attempts, I got it to work once. Since then I tried 3 times and failed. You are supposed to see 3 lines when it reads the blood sample, but I didn't get even one. I set the lancet to the maximum setting (5) and following advice I read on the forum, I moved my arms around and held my hands under hot running water before taking the last test. No change registers on the meter when I try to take my sample. Does it sound like a meter problem, or have I just not got the hang of it yet? I bought a Freestyle lite meter yesterday. After a few attempts, I got it to work once. Since then I tried 3 times and failed. You are supposed to see 3 lines when it reads the blood sample, but I didn't get even one. I set the lancet to the maximum setting (5) and following advice I read on the forum, I moved my arms around and held my hands under hot running water before taking the last test. No change registers on the meter when I try to take my sample. Does it sound like a meter problem, or have I just not got the hang of it yet? I'm not sure why you mentioned lancet depth setting. Are you thinking it wasn't enough blood? That meter uses the tiniest amount of blood among all meters. You do know that you have to put one of the SIDES of the strip into the blood drop, not the tip, right? If you see a drop of blood, correctly put one of the two SIDES of the tip into it you should hear a beep acknowledging successful sample. I any of this doesn't happen, that explains it. If the strip is inserted correctly (the display shows a drop indicating it is ready for a sample), you put the right part of the strip into it and it beeped sample confirmation and still didn't give a reading, then you may have a defective meter. << Nothing I say or expres Continue reading >>

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 >>

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 >>

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