Diabetes Machine Round Up

Mar 5, 2019

By: Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy

"That's right big guy. Put the pod in the coffee machine. Put some cream in the cup. Put the cup under the machine. Add water to the machine. Hit the button. I can smell the coffee. Excellent. Wait! Wait! You forgot the most important part. Sigh. I guess I'll just have to bark at you again." Sheldon has a very expressive face. I'm sure he has very complex thoughts about how he is training me for "Coffee-Cookie time". Every morning he is there at my side staring at me. And if I don't give him a cookie when I'm done making a cup of coffee, I am corrected with a loud, sharp bark. I think Sheldon's training of me is almost complete.

We do a lot of training of people in the pharmacy learning to use blood sugar machines. There have been lots of questions about blood sugar machines lately. The Freestyle Libre is "that machine where you don't poke your finger". I'm sure I'm asked about it at least once a week. Everyone is excited about checking their blood sugar without poking themselves just like they see on TV. Well... it isn't quite as easy as TV makes it seem.

I'm not trying to poo-poo the Freestyle Libre. It does seem like a good machine. And you really don't have to poke your finger. But it isn't quite as easy as it seems on TV. The first thing is, there is poking. The Freestyle Libre sensor does poke into your arm. It is a small round disk and you stick it onto the tricep area of the back of your upper arm. It does have a pokey probe that will break the skin and stick into your arm. But instead of poking your finger several times per day, you only have to replace the sensor on your arm once every two weeks. That definitely is more convenient. To read your blood sugar, you bring the meter, known as the reader, within 4 cm of the sensor and the reader talks to the sensor wirelessly.

Most of my conversations about the Freestyle Libre don't end with people getting the machine. And the reason is not that it doesn't work and not that the person doesn't like the idea of a sensor sticking in their arm for 2 weeks. Unfortunately, the Freestyle Libre is expensive. The sensor that you have to change every 2 weeks is about $110. The reader is about $70. You only have to buy the reader once, but you'll have to spend about $220 per month on sensors. So that is usually where the Freestyle Libre conversation ends.

An interesting study about regular "poke your finger" blood sugar machines recently came out. The first interesting thing is it wasn't run by a blood sugar machine manufacturer. It was run by the Diabetes Technology Society. They are a group of medical doctors and PhD researchers who wanted to know how accurate blood sugar machines were. They published their results in the August 2018 Diabetes Care. They had 1035 patients. The study was conducted from 2016 to 2017. They had non-diabetics, type 1 and type 2 diabetics in the subject group. The researchers bought the machines and strips at pharmacies and online from all over the United States. All the finger poking was done by health care professionals to eliminate poor meter usage as an error source. The results from the blood sugar machines were compared to a lab values. The researchers called their study triple blinded. The people reading the machines didn't know the lab values. The people at the lab didn't know the blood sugar machine values. The people who did the math on the results didn't know which result came from which machine. The group tried hard to keep their results unbiased.

How did the blood sugar machines do? Well they did terrible, or great, or somewhere in between. First, this was an American study, so there were 18 machines on the list and most aren't available in Canada. And that is okay, because most of the ones not available in Canada did very poorly. The ones available in Canada were the Contour Next, Accu-Chek Aviva, FreeStyle lite, OneTouch Verio and OneTouch Ultra 2. How they did depends on which standard you looked at.

The old standard by which Health Canada considered machines accurate was if they were within 20% of the lab value 19 times out of 20. By that standard, all the Canadian machines passed. The new Health Canada standard is machines should be with 15% of the lab value 19 times out of 20. Using the 15% standard, Contour Next, Accu-Chek Avia and FreeStyle Lite all passed and the OneTouch Verio and OneTouch Ultra 2 failed. And if you keep going, only Contour Next passed being within 10% accuracy and all the meters failed miserably at being within 5% accuracy.

Do these results matter to me as a patient? If you do not use insulin, probably not. Let's say your blood sugar was really 10 mmol/L. A machine that has a 20% accuracy error rate means it could show you a reading anywhere from about 8 to about 12. That is probably not going to affect your day much. And your doctor is going to adjust your medication based on your HgA1c, which is a 3 month average of your blood sugar readings, not based on your blood sugar machine readings. So just be aware that your blood sugar machine might be giving you results that close to your actual number, but not super accurate.

If you use insulin, this study is quite important. You really might inject more insulin if your machine reads 12 mmol/L instead of 8. So, if you use insulin and you use the OneTouch Verio or OneTouch Ultra 2, it might be time to talk to your pharmacist about an upgrade.

Sheldon knows the sound and the smell of the coffee machine means it's time for Trevor to give you cookies. If you are diabetic you will have triggers that tell you it is time to check your blood sugar. And testing your blood sugar is an important way for a diabetic to take control of their condition. If you have any problems or questions about testing your blood sugar, please call your pharmacist. But don't bark at us. Well maybe I'm wrong about that too. I'm sure Sheldon would tell you training a pharmacist works well when you bark at them to correct their behavior.

The information in this article is intended as a helpful guide only. It is not intended to be used as a substitute for professional advice. If you have any questions about your medications and what is right for you see your doctor, pharmacist or other health care professional.

We now have this and most other articles published in the Parkland Shopper on our Website. Please visit us at www.dcp.ca

  1. Libre - https://myfreestyle.ca/en/products/libre?gclid=Cj0KCQiAzePjBRCRARIsAGkrSm4sHN59hOSnTyNevzXcG5zuNsxV-Vp2Bd6Ge7vy5ltH3IJIjo8wfEoaApdCEALw_wcB
  2. of the Accuracy of 18 Marketed Blood Glucose Monitors- http://care.diabetesjournals.org/content/41/8/1681

Notice: New Requirements for Medical Device Licence Applications for Lancing Devices and Blood Glucose Monitoring Systems - https://www.canada.ca/en/health-canada/services/drugs-health-products/medical-devices/activities/announcements/notice-new-requirements-medical-device-licence-applications-lancing-devices-blood-glucose-monitoring-systems.html

 


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