How Accurate Are Blood Glucose Test Strips?

Diabetes management is a very sensitive issue in society today; blood glucose test strips help people with diabetes to easily and quickly regulate their blood sugar levels. When used with a blood glucose meter, these strips can give valuable information about blood glucose patterns and enable individuals to adjust their insulin doses, diet, and physical activity.

Blood Glucose Test Strip Accuracy Standards 

There are strict standards that have been put in place by the regulatory authorities including the U.S. Food and Drug Administration (FDA) and the International Organization for Standardization (ISO) that must be met by blood glucose meters and test strips.  

ISO Accuracy Standards 

The ISO 15197:2013 standard specifies that: The ISO 15197:2013 standard specifies that: 

• For blood glucose below 100 mg/dL, 95% of the glucose readings have to be within 15 mg/dL of the true laboratory value. 
• For blood glucose levels of 100 mg/dL or more, 95% of the readings should be within ±15 percent of the true value. 

This means that when the actual blood glucose level is 80 mg/dL, the test strip should give a value between 65 and 95 mg/dL in 95 percent of the cases. When the reading is 150 mg/dL, the result should be around 127.5 and 172.5 mg/dL in 95 percent of the cases.  

FDA Accuracy Guidelines 

 The FDA requires that: 

• 95% of readings should not be more than ±15% from a true laboratory value. 
• 99 percent of the readings have to fall within ±20 percent of a true laboratory value. 

These guidelines make test strips provide fairly accurate results, but there could still be a little error. Although such deviations may not appear very large, they can mean a lot when it comes to the dosage of insulin, particularly for patients with well-controlled blood glucose. 

Factors That Affect the Accuracy of Blood Glucose Test Strips 

Although glucose test strips are manufactured to conform to some requirements set by regulatory bodies, several elements can affect the strips’ accuracy. Some of these factors are fixed on the design of the strips while others depend on how the strips are handled by the users or on the prevailing conditions. 

1. Manufacturing Variations 

Despite the manufacturers’ best efforts to ensure that the same product is produced over and over again, there are always minor differences. However defective strips can sometimes make their way to the consumers, although this is rare. This is why it is recommended that one should always use test strips that come from a reliable manufacturer that meets the ISO or FDA standards.  

2. Improper Storage Conditions 

The accuracy of glucose test strips is another important factor where storage is considered to be very important. The chemicals used in the strips are known to be affected by environmental factors such as temperature, humidity, and light. Here are a few guidelines for storing strips properly: 

• Keep them in a cool, dry place: Do not expose strips to heat because high temperatures will shorten the enzyme’s stability and activity. Store strips within a range of 59°F and 86°F (15°C and 30°C) for the optimum condition of the strips. 
• Avoid moisture: Humidity can affect the chemical reaction that takes place in the strip and therefore it is recommended that they are stored in a dry place. 
• Seal the vial tightly: Ensure that one closes the vial tightly each time one takes a strip to avoid contact with both air and moisture. 

3. Using Expired Strips 

The blood glucose test strips have a validity date which must be strictly observed because the strips may produce false results when used beyond the date. The enzymes on the strips also get denatured and thus reduce their ability to recognize the glucose in the blood. One must always ensure that the strip comes from a vial with an active expiration date and that the box that contains the strips also has an active expiration date. 

4. User Error 

These errors include;

• Insufficient blood sample: Most glucose meters and strips need a fixed volume of blood to produce the right test result for blood sugar levels. An inadequate blood sample might lead to an incorrect reading or the inability to do the test at all. 
• Improper strip handling: Rubbing the test area on the strip with fingers can compromise the strip and therefore alter the results.
• Using the wrong strips: Make sure that you are using the right strips for your meter all the time. Each meter needs strips that have been specifically designed to work with that particular meter. 

5. Substances on the Skin 

If the hands are not washed, there are high chance that other materials such as food residues, lotion, or dirt will contaminate the blood sample which may produce wrong results.

Conclusion 

Blood glucose test strips are relatively accurate provided the procedures involved in their use and the conditions of storage are observed. It is very important to know that no strip in the market can give you a perfect result all the time but the modern strips for glucose are very accurate and are developed with very high standards. However, the behavior of the individual users, the conditions in the environment, as well as the quality of the strips used can affect the results. The above factors if well understood and practiced as recommended by the manufacturer can enable one to have accurate blood glucose readings and, hence better diabetes management.

FAQ’s

Q1. For how many hours do the blood glucose test strips remain valid before expiring? 

Most blood glucose test strips have a shelf life of 3 to 6 months after the test strips have been opened. It is important to use the products before the expiration date on the pack and keep them in a cool and dry place. 

Q2. Can I be harmed by using expired blood glucose test strips? 

Indeed, if one uses expired test strips, he or she is likely to get the wrong results. The enzymes on the strip are also affected by the passage of time and therefore are unable to give accurate results of blood glucose. It is recommended that new strips should be used to make accurate measurements to avoid high or low results due to expired strips.  

Q3. What causes variation when using the blood glucose test strips? 

The variation in the readings can be explained by aspects such as inadequate blood samples, wrong storage of strips, environmental conditions, or dirty hands. This helps increase the accuracy of the strips and should always follow the manufacturer’s instructions on how to store the strips.

ANTITECK provide glucose strip production line for glucose test strips manufacturing, contact us for more information via [email protected]

Maybe you also like:
How To Manufacture Glucose Strip?
How To Manufacture Urine Test Strips?