How accurate are the home blood glucose meters that diabetics rely on? We tested 10 models

Dad Review, in collaboration with Zhejiang Institute of Metrology (hereinafter referred to as the Institute of Metrology) and the official authoritative media Hangzhou.com, conducted an evaluation of home blood glucose meters.

The "Market Weekly" column co-organized by Zhejiang Provincial Market Supervision and Administration Digital Media Center and Zhejiang Economic TV also followed up on this evaluation.

Through solicitation with fans and friends, we have selected 10 common and high-selling portable blood glucose meters on the market. The sample information is as follows:

This article will expand on five aspects: product principles, evaluation steps, experimental results, precautions, and purchase recommendations. I hope it can help friends in need.

1. Product Principle

Although there are various types of blood glucose meters on the market, according to our investigation and survey by Zhejiang Economic TV's "Market Weekly" column, many patients have doubts about its accuracy.

The test results of blood glucose meters from different brands are different, and the test results of blood glucose meters and hospitals are also different. So where does the gap come from?

Portable blood glucose meters measure "fingertip whole blood glucose", while hospitals test "venous plasma blood glucose".

The former (whole blood) contains red blood cells, while the latter (plasma) removes red blood cells, which have a lower glucose content. The difference can be seen here. In addition, the hematocrit and oxygen content of fingertip and venous blood are different, which will also affect blood sugar levels.

In order to help you choose a high-quality blood glucose meter and effectively manage your disease, let us first explain to you the working principle of the blood glucose meter:

Therefore, the accuracy of the conversion process will also affect the accuracy of the blood glucose meter readings.

According to the national standard GB/T 19634-2005 "General Technical Requirements for Blood Glucose Monitoring Systems for Self-Testing in In Vitro Diagnostic Test Systems", the allowable deviation of blood glucose meters is ±20%.

Then even if the results measured by two brands of blood glucose meters differ by 40%, it is possible that both results are "correct".

2. Evaluation

Zhejiang Provincial Institute of Metrology, referring to the calibration methods commonly used in hospitals, designed the following scheme for this evaluation: The introduction of a reference analyzer solved the problem of the inapplicability of using serum surface substances to directly verify the blood glucose meter;

Xie Zhuoli, an engineer from the Institute of Metrology, explains the reference analyzer

Considering that consumers use fingertip blood when measuring blood glucose in their daily life, a certain amount of fingertip whole blood was taken from each volunteer for comparison.

01 Reference Standards

The standards referenced this time are as follows:

Currently, the national standard corresponding to portable blood glucose meters is GB/T 19634-2005 "General Technical Requirements for Self-Testing Blood Glucose Monitoring Systems for In Vitro Diagnostic Test Systems". This standard is derived from the 2003 version of the international standard ISO 15197 "In Vitro Diagnostic Test Systems - General Technical Requirements for Self-Testing Blood Glucose Monitoring Systems for Diabetes Management".

From the sample information chart at the beginning of the article, we can see that some samples implement ISO 15197:2013. The difference between the latter two is that in the latest version of the international standard, higher accuracy requirements are required, which reduces the allowable error range.

Therefore, for this blood glucose meter evaluation, we refer to the requirements of the latest version of the standard ISO15197:2013.

02 Experimental Phase

Experimental location: Zhejiang Provincial Joint Laboratory of Medical Metrology and Quality Control

Experimental subjects: 10 volunteers (recruited by the experimental team, including patients with normal blood sugar and hyperglycemia)

Operator: Hangzhou Shangcheng District Ziyang Street Community Health Service Center (to ensure the accuracy of blood collection method)

Preparation:

According to the hematocrit range required by the 10 blood glucose meters, volunteers underwent routine blood tests in the hospital in advance to ensure that the volunteers' hematocrits were within the range of 35%-50%.

Reference Analyzer Verification:

The reference analyzer was checked with serum glucose standard materials of different concentration gradients, and the results showed good accuracy and could be used as standard blood glucose values.

Operation process:

1. Take a certain amount of whole blood from the fingertip of each volunteer, and test a part of it with a reference analyzer. Repeat 3 times in parallel and take the average value. After correction for each volunteer's hematocrit, the standard blood glucose value is obtained.

2. The remaining blood samples were tested in turn using 10 blood glucose meters according to the blood glucose meter instructions. Each volunteer's blood sample was measured 3 times, and the average values ​​were taken to obtain the blood glucose meter measurement value.

3. In addition, 5 volunteers were tested again 1 hour after meals to obtain blood sugar results in different concentration ranges.

By comparing the blood glucose meter's measured value with the standard blood glucose value, the error can be obtained, and the deviation (accuracy) of the blood glucose meter can be known.

03 Experimental Results

The test results of different volunteers were divided into two groups according to their blood sugar concentrations: low blood sugar concentration (lower than 5.55mmol/L) and high blood sugar concentration (higher than 5.55mmol/L).

The reference allowable error for low blood glucose concentration is ±0.83mmol/L, and the reference allowable error for high blood glucose concentration is ±15%.

Based on 15 sets of test data provided by 10 volunteers, we drew an error point distribution diagram for each blood glucose meter sample.

The two curves in the figure represent the error limits, and each point represents the error value of each measurement.

If the point is between the two lines, it means that the measurement result meets the requirements; if the point is outside the two lines, it means that the measurement is out of tolerance.

Based on the test results, we invited Dr. Chen Can from the Institute of Metrology to analyze and interpret:

The experimental results show that the overall measurement results of the 10 blood glucose meters performed well, among which 4 blood glucose meters showed certain deviations (exceeding the standard limit value).

It can be seen that blood glucose meters can only be used to monitor patients' fasting blood glucose and record blood glucose changes over a period of time. They cannot replace the blood glucose test results of laboratories and hospitals as a standard for adjusting medication and as a basis for diagnosis.

3. Why do we need to do this evaluation?

From 1980 to 2017, the prevalence of diabetes in my country soared from 0.67% to 11.2%.

The "Global Diabetes Overview (9th Edition)" published by the International Diabetes Federation states:

As of 2019, there were approximately 116.4 million diabetes patients in China among people aged 20 to 79, ranking first in the world.

That is to say, about 1 in every 13 people in our country suffers from diabetes. The high prevalence and the large number of confirmed cases are evident.

For people with diabetes, hyperglycemia and gestational diabetes, "measuring blood sugar" has long become a daily routine, just like eating and sleeping.

Because portable blood glucose meters have the advantages of simple operation, rapid detection, small blood collection volume and little pain, they have become a must-have in the homes of many diabetics.

For most patients, a "easy-to-use" portable blood glucose meter seems to be a "life-saving talisman".

But for the father of netizen @User7524087011, this is not the case...

The netizen who posted the post is from a city in Yunnan. He said that his father had been using a certain brand of blood glucose meter to measure his blood sugar level. During the period of use, the test results remained high for a long time, which made his father very nervous and he kept increasing the dosage of hypoglycemic drugs.

Afterwards, my father became weak and had to be hospitalized for treatment. However, after a reexamination at the hospital, it was found that there was a 40% - 60% error between the two.

The father's actual blood sugar level was 15.4mmol/L, but the blood sugar meter showed 25.1mmol/L. Due to lung infection and low immunity, the netizen's father eventually passed away.

Although the direct cause of this tragedy was not the blood glucose meter itself, the father, who originally weighed more than 160 pounds, was starved to death, unable to sleep at night, and suffered physical and mental torture that he should not have endured during the period when he was misled by the blood glucose meter readings.

The weight of life is unbearable for family members.

After seeing the article by netizen @User7524087011, it occurred to me that many of our fans have expressed the need to review blood glucose meters, so Dad Review joined forces with all parties to carry out this blood glucose meter review.

In addition to the deviation of the portable blood glucose meter itself, improper operation when measuring blood glucose will also affect the results.

We have summarized the "Blood Glucose Meter Usage Tips" for your reference:

Purchase suggestions:

1. Pay attention to whether the manufacturer is legitimate, do not trust product promotion and buy products without any warranty. It is recommended to choose a reputable brand with after-sales guarantee services and convenient purchase of matching test strips;

2. Give priority to electrochemical blood glucose meters, which have smaller errors, reduce the chance of retesting, and avoid misleading patients;

3. It is recommended to choose a siphon blood collection blood glucose meter, which is easier to operate and will not cause deviation in results due to too much or too little blood;

4. Choose a blood glucose meter with a memory function to facilitate observation and recording of blood glucose changes;

5. For those with poor eyesight or parents and elders, it is recommended to buy a blood glucose meter with a large screen and fast reading speed (results can be obtained within 6 seconds), which is convenient and quick.

For patients with hypertension, diabetes, and gestational diabetes, acupuncture, medication, and diet control have become their daily routine.

Portable blood glucose meters can only be used as a tool for daily monitoring of blood glucose changes, rather than a basis for diagnosing medical conditions.

If the readings are frequently abnormal, you should seek medical attention promptly and increase or decrease medication based on the hospital's blood sugar test results and doctor's orders.

Hyperglycemia and diabetes are chronic diseases that, once diagnosed, will most likely be lifelong.

It is like a ferocious beast with an unstable mind. A sip of milk tea or a piece of biscuit may make it run wild and violent. It may drag your body to the edge of the cliff, and a gust of wind may make you fall into the abyss from which there is no escape.

The blows it brings to people are progressive. After finally getting through one level, it hits people hard again, causing their emotions to rebuild and then collapse over and over again. By the end, they lose their spirit.

We regard it as a sudden accident, but we don't know that it is the accumulation of all kinds of expected things. In addition to seeking medical treatment and cooperating with treatment, an optimistic, positive and optimistic attitude is always the best medicine for curing diseases.

After you have overcome this hurdle in your heart and look back, you may find that the changes in your life are not as great as you imagined.

The environment is created by the mind, and things change with the mind; if the mind is strong, you will not be afraid of the difficulties on the road; if the mind is as clear as a blue sky, there will be scenery everywhere.

References: [1] Chinese Diabetes Society. Guidelines for the prevention and treatment of type 2 diabetes in China (2020 edition) [J]. Chinese Journal of Endocrinology and Metabolism, 2021, 37(04): 311-398.

[2] International Diabetes Federation. Global Diabetes Overview (9th Edition) [R]. IDF Global Diabetes Overview

[3] GB/T 19634-2005, General technical requirements for blood glucose monitoring systems for self-testing in vitro diagnostic test systems[S].

[4] ISO 15197 “In vitro diagnostic test systems – General technical requirements for self-diagnostic blood glucose monitoring systems for the management of diabetes mellitus”

[5] Zhang Ju. Exploring the effect of vitamin C on some test items in blood tests[J]. Chinese Practical Medicine, 2019, 14(33): 80-81.