There are often discrepancies between blood glucose meter results and laboratory test results. Is it because the blood glucose meter is inaccurate? Or is there another reason? In many cases, errors in blood glucose meter test results are caused by the users themselves, which mainly include the following subjective factors:
1. Blood sugar fluctuations are inevitable
2. The blood glucose meter and test strips do not match
Patients must choose blood glucose test strips that match their own blood glucose meter. Even different models of blood glucose meters produced by the same manufacturer use different test strips.
3. No code correction
Each bottle of blood glucose test strips usually comes with a specific code, and each time a new box of test strips is used, the code on the blood glucose meter must be adjusted to match the code of the test strips currently in use. Otherwise, the test results will be affected.
Now, the coding-free blood glucose meters on the market can automatically recognize the test strip code, so this step can be omitted.
4. Improper cleaning and disinfection
Be sure to wash your hands before taking blood, otherwise substances stuck to your hands may affect the accuracy of the test results.
Since iodine disinfection can cause deviations in test results, 75% medical alcohol should be used to disinfect the skin when collecting blood, and be sure to wait until the alcohol has completely evaporated before inserting a needle to collect blood, otherwise the alcohol will dilute the blood and destroy the reaction enzymes on the test paper.
When the blood glucose meter displays a blood drip signal, drip blood from your fingertip onto the blood sample area of the test paper. The amount of blood drip should not be too much or too little. It is appropriate for the blood drip area to completely turn red.
5. The depth of blood collection needle is not enough
The depth of the needle for blood collection is not enough. The patient's skin is thick and the blood collection needle is shallow. Due to insufficient blood loss, the blood collector squeezes the finger hard, causing tissue fluid to mix into the blood, diluting the blood and causing low blood sugar levels.
6. Improper operation methods
The operating procedures of various blood glucose meters are similar. When testing, patients must first read the instructions in detail and correctly master the operating methods of the blood glucose meter.
Common incorrect operations include:
①The test strip is not completely inserted into the bottom of the test hole during testing.
② Some instruments drop blood first and then insert the test strip into the blood glucose meter. If you wait for more than two minutes after dripping blood before inserting the test strip into the test hole, the test result will be inaccurate. In this case, you should use another instrument. Retest with new test strip.
③ Movement of the test strip during testing will also affect the test results. Therefore, the blood glucose meter should be placed in a stable and safe place for use.
7. The test strips are stored improperly or the validity period has expired.
Test strips are required to be stored in a cool, dry, and dark place. They must not be exposed to moisture or sunlight, and cannot be stored in a refrigerator.
When using bottled test strips that are not individually packaged, it is required that the bottle cap be tightly closed immediately after taking out the test strip. It is not advisable to expose it to the air for too long. Otherwise, the test strip in the box may easily become damp, contaminated, or chemically interact with certain substances in the air. reaction, affecting blood glucose test results.
The test paper should be used up within the specified validity period. Do not use test paper that has expired, otherwise it will affect the test results.
8. The blood glucose meter was not calibrated, cleaned and maintained in time.
The blood glucose meter was not calibrated regularly. Generally, blood glucose meters produced by official manufacturers have after-sales service. You need to go to the store where you purchased it or the manufacturer's designated place to calibrate the blood glucose meter regularly (about half a year) to see if it is accurate.
The blood glucose meter was not cleaned and maintained in time. When the blood glucose meter has dirt or blood stains, especially when the test area of the instrument is contaminated, the test results will be affected. At this time, you can use a soft cloth dipped in water to clean. Do not use detergent to clean or let water seep into the blood glucose meter. Do not immerse the blood glucose meter in water or rinse it with water to avoid damaging the blood glucose meter. In addition, the allowed working temperature of the blood glucose meter is 10℃~40℃, and the humidity is 20%~80%. Too cold, too hot, and too humid will affect its accuracy.
9. The battery of the blood glucose meter is low.
After the blood glucose meter has been used for a period of time, if the word "low battery" or symbol appears on the display screen during the test, it is considered that the battery power is insufficient, and the battery should be replaced with a new one in time.
10. Influence of other factors
Many people with diabetes also suffer from other diseases. For example, patients with high blood lipids have oily blood, which will cause errors in the colorimetric light reflection, thus affecting the results. Some patients take multiple medications, and these medications contain certain substances that can affect blood sugar test results.
In addition, there are objective differences between blood glucose meter test results and laboratory test results. The blood glucose meter measures the blood sugar of capillary whole blood (including red blood cells and plasma), while the hospital laboratory draws blood to measure the blood sugar of venous plasma after removing red blood cells. Since glucose in red blood cells contains less sugar, the blood sugar value in venous plasma in the fasting state is usually about 10% higher than the blood sugar value in capillaries. However, this is a proper difference between the two. We cannot blame the blood glucose meter for being "inaccurate" ”, but the difference is caused by different specimens.
We should know that the human body's blood sugar level is affected by many factors such as diet, exercise, drugs, psychology, etc. It is not fixed but fluctuates frequently throughout the day. Blood sugar will rise after a meal and then gradually decrease. Fasting blood sugar is different from post-meal blood sugar, and blood sugar 1 hour and 2 hours after a meal is also different.
Not only are blood sugar levels different at different times of the day, but blood sugar levels are also different at the same time on different days. Therefore, there will naturally be certain differences in blood sugar levels depending on the testing time. Take fasting blood glucose on different days as an example. You don’t have to expect the results to be the same twice. As long as the measured value does not change much, it is completely acceptable. There is no need to be nervous about a little fluctuation.
It is undeniable that the quality of some brands of blood glucose meters is indeed not up to standard. But based on most of the above situations, it can be found that many problems are not with the blood glucose meter.
The values measured by the blood glucose meter are often not completely consistent with the results measured by the hospital laboratory. This is normal. Blood sugar values are also greatly affected by blood oxidation. The blood glucose meter gives a relative standard value, so the result is Mainly hospitals.
