I am going trekking in Grand Canyon for four days, followed by a trip to Sin City for four days, all in the 40 degree heat of August. To help manage my Type 1 Diabetes I am going to wear all four CGM systems, to put them to the test and see which comes out on top! If you have Type 1 diabetes and are interested in CGM, my future experience may be of use. Which systems will I be using?
· The Abbott Libre - To be known as Libre from now
· The Dexom G5 - To be known as G5 from now
· Medtronic VEO with Enlite Sensor - To be known as VEO from now
· Medtronic MiniMed 640G with Enlite Sensor- To be known as MM604G from now
Why am I hooking myself up to four different CGM systems at the same time?
1. I am person with Type 1 diabetes who believes combining empowering self-management education with technology is currently the most effective way to achieve good control, whilst living a life with no limits. So I want to know which is the best CGM system and how to use it best.
2. I work as Diabetes Educator for Children with Type 1 Diabetes and it is obvious to see the fast move toward using CGM in place of finger sticks, it's just a matter of time, and that time is drawing near. I want to have excellent technical and practical knowledge of the main systems so I can help children and families select a CGM system that will suit them best, whether it is funded by the NHS or personally.
3. I am going to be in the middle of Grand Canyon with little access to medical treatment and supplies, so having four systems means I will be full proof. After Grand Canyon I go to Las Vegas for four days, so seeing how the City of Sin impacts on diabetes management could also be an interesting insight.
The questions I am going to be addressing with this CGM experience are:
Which CGM systems' sensor glucose (SG) is the most accurate compared to finger prick blood glucose (BG) ?
· I have created spreadsheet to calculate the Mean Average Relative Difference (MARD) of each CGMS systems' SG compared to my BG. I will be testing at meal times and occasionally when the systems suggest I am hypo. At present the studies suggest the below MARD, and I want to see if they are that accurate for me:
o Libre - 11.3%
o G5 - 9.0%
o VEO - 13.0 -14.0%
o MM640G - 13.0-14.0%
o Real life speak; MARD is how different on average the SG reading is compared to the BG. Therefore if the BG is 10.0mmol/l you would on average expect the SG for the different CGM devices to be between:
§ Libre - 8.9 - 11.1 mmol/l
§ G5 - 9.1 - 10.9mmol/l
§ VEO - 8.7 - 11.3mmol/l
§ MM640G - 8.6 - 11.4mmol/l
· I am going the present to above data in two ways;
o Firstly, using the time periods suggested by the manufaturers specifications e.g. Enlite sensor for VEO and MM640G 6 days, Libre 14 days, Dexcom G5 7 days. This will show the accuracy and cost to the user and NHS when used to specifications.
o Secondly, using the sensors for as much time as possible to see how accurate they are past specifications, and in truth how they are being used by the diabetes community. This will show how much a user would expect to pay if self-funding, and what are the trade offs in accuracy.
What would be the impact on my diabetes control if I made therapy decisions (correction doses and treating hypos) on SG readings in place of BG readings? Will one CGM system come out on top?
· G5 has both CE mark and FDA approval for people with diabetes to use the SG readings for giving correction insulin doses and treating hypos. The Libre has CE mark for the same and is submitting the FDA for potential approval by the end of 2016 . The VEO and MM640G do not have CE mark or FDA approval for the above, but they do for Low Glucose Suspend (FDA & CE) and Smart Guard: Predictive Low Glucose Suspend (CE) technology, respectively.
· I have created spreadsheet to calculate the correction doses that I would give based on each of the SG readings at meal times. The spreadsheet uses my correction factor to show the difference in mmol/l my BG would be if I used the SG of the different CGM systems in place of my BG reading. This will allow me to see if on average it appears safe and if there are any times that would not be safe e.g. very high BG readings or just after a heavy bout of exercise.
What are the key features and unique selling points of each and how do they trade off against each other:
o Libre - Easy set up and low profile, no alarms, no finger pricks at all, rate of glucose change arrows
o G5 - Connectivity, high and low alarms, rate of change alarms & arrows
o VEO - Connectivity, high and low alarms, rate of change alarms & arrows, low glucose suspend
o MM640G - Connectivity, high and low alarms, rate of change alarms & arrows, Smart Guard: Predictive low glucose suspend
I will rank each CGM system on different key areas:
· Ease of use
· Key safety features
· Key features for proactive management
· Value for money at manufacturers specification
· Value for money at practical level use
Finally once I have all the data I will put down my thoughts on the groups of people who may benefit the most from different systems. I will highlight the current CGM funding environment of the NHS and where these devices fall within or outside them. The four key guidance documents being:
1. NICE Type 1 adults - updated 2015
2. NICE Type 1 Children - update 2015
3. NICE (2016) DAP on sensor augmented pumps - Released Feb 2016
4. NICE (2016) Quality Standard 4 on CGM for children and young people - Released July 2016
If you know anyone who may benefit from this type of information and analysis please share this with them.
Please bear in mind I am doing this for fun, a hobby, to learn, to teach, and to help others. I am not doing it to market anything or become a blogging icon. So if I do not respond to messages or comments it is not because I do not care, I will just be busy living life (well attached to four devices!).
I hope you enjoy it.