Is my monitor up to standard?
Monday, 30 January 2017
When testing your blood glucose levels (BGLs) you want to be sure that your monitor is as accurate as possible.
It’s important to make sure it suits your needs, and the best way to find the right one is to chat to your diabetes educator or pharmacist. They can also provide you with additional information, further instruction and support.
Once you have a monitor take the time to read through the manual. This will tell you how to change the time and date (for day light saving, travel), troubleshoot problems and the correct testing technique to use (eg how to insert the test strip).
Once you’re comfortable with your monitor choice, it’s important to know your testing times, the target range for your results and what you need to do when your BGLs are outside your range. Talk to your doctor or diabetes educator about your times, target levels and what action to take.
Many monitors have inbuilt recording of results, however, if you have a doctor’s visit it’s always a good idea to write down your results for a couple of weeks prior to the appointment. Add in any comments such as sick day, extra activity or carb amounts at meal times.
Why am I getting different results when I test twice?
People sometimes ask why testing the same finger twice may give different results. This can be because the first drop of blood is thicker with more concentrated blood cells so the result may be slightly higher than the second drop. Some educators and monitor companies will recommend wiping away the first drop and using the second.
If you have unpredictable results it may be time for a review of you monitor and testing method with your diabetes educator. If a result is much higher or lower that you usual ones, repeat the test with re-cleaned hands. It may be that your blood glucose level is accurate so compare this with any symptoms you may feel. Many situations effect your levels such as medications like steroids, sickness or stress.
Errors in your results can happen especially if you don’t have clean hands or struggle to obtain a drop of blood. Environmental factors such as temperature can still effected the accuracy of the result as well.
You can check the accuracy of your monitor using control solution, which provides a pre-determined result range. If your monitor doesn’t return the same result as the range listed on the control solution bottle, your monitor is likely to be faulty. Manufacturers will replace faulty monitors if they read outside the range and will also provide you with control solution free of charge.
So how do I know what I am buying?
All monitors sold in Australia for people to test their blood glucose level must meet the international standard called ISO 15197:2013 by May 2016.
This works to ensure reasonable accuracy. BGL results from the monitor are compared to laboratory measurements. These comparison tests also cover whether the accuracy of the result in effected by other interferents (a substance that results in an incorrect result) such as drugs like ibuprofen, the volume of red blood cells (haematocrit level), or cholesterol levels. There are twenty four different interferents tested for. How the monitor is used is also evaluated to ensure user error does not compromise the result.
To achieve the ISO standard, 99% of the results must be within 15% (plus or minus) of the true result. For ISO 2013, for an actual true value of 5.0 mmom/L the result must fall between 6.0 and 4.0 to be accurate.
The previous standard (ISO 2003) was 95% of the results must be within 20% (+/-).
The new standard has meant that more accurate monitors are available in the market.
Figure 1: An example of the standard – the true value is a blood glucose level of 5.0mmol/L
New + 15% True Value -15%
ISO 6.0 5.0 mmom/L 4.0
Old + 20% True Value -20%
ISO 7.0 5.0 mmol/L 3.0
What does this really mean?
Your monitor may be 1 to 2mmol/L higher or lower than your actual BGL depending on your monitor type and if it meets ISO 2013. Health professionals understand this. Remember monitors older than 2013 may only meet the 2003 standard and are therefore are not as accurate.
How do I find out if my monitor meets the standard?
The quickest way is to do a “google” search online for ISO 2013 and your monitor name. This should provide a simple statement such as “meets ISO standard 15197:2013”. It can also often be found on the manufacturer’s information supplied with a monitor or you can contact the manufacturer’s customer support.
We’ve done the research for the monitors that we sell. All monitors listed below are ISO 2013 compliant and available from diabetesshop.com
Dario Smart Meter
Freestyle Optium Neo
Caresens N POP
OneTouch Verio IQ
Other brands of monitors we sell meet the current ISO 2003 accuracy standard and more recently manufactured versions of these monitors may also be ISO 2013 compliant.
If you need to update your monitor you can chat to your diabetes educator who can show you the range of monitors currently available or you can call us to speak to one of our diabetes educators or visit diabetesshop.com for more info.
To speak to a Credentialled Diabetes Educator call the NDSS Helpline on 1300 136 588.