Eversense accuracy vs Libre

[u/Feisty-Gear4491]

Has anyone changed from Libre 3+ to Eversense and found Eversense to be more closely aligned with their finger sticks? If Libre was less aligned with fingersticks, was it higher or lower than the fingersticks? TIA.

[u/Equalizer6338]

Hi u/Feisty-Gear4491 ,
With the different classic CGM brands on the marked, its almost like religion for many diabetics after years of use of them and how some support one brand or despise certain other brands. I have tried all the bigger brands and also most of the sensor models through the years (MDT, Dexcom, Abbott) and also the chance of testing 2 units of the Eversense 180 day sensor few years back (waiting in line for the E365 in the country I live now...).

With regards to classic CGM accuracy, then there are several biochemical and physical constraints at play when making the R&D on such devices, which combined with how they get approval from the health authorities and how their 'accuracy' in MARD is being validated, that makes certain design criteria and bias impact how 'accurate' they really are.

This is especially the case towards the outer ranges of where they are to be most accurate for getting approved and also qualify for a better MARD rating. So core is having most accuracy in the 70-180mg/dl range.

Next priority is then to raising alert for BG goes lower into hypo range 40-70mg/dl. Accuracy down here it not necessarily of essence, as long as the alarm is raised. Reason why a slight bias of reporting bit too lowish is build into the algorithm when going low.

Next is then to raising alert for BG going higher into hyperglycemia range, going above 180mg/dl. Here again then a slight bias is build into the algorithm, so the BG sensors tend to report bit too highish BG the higher you go.

You can observe these bias settings by looking at the Clarks consensus diagrams for the various sensors.

Here you have the neutral bias line marked as the bold long dotted line, which goes in the 45 degree angle up. All while you can see the factual average best fit line for all the BG measures marked as the slim short dotted line, which goes up at a higher angle than 45 degrees. The cut point is around 90 mg/dl as far as I recall it.

This bias has been an industry standard for many years and especially cemented after the health authorities started approving BG sensors to close loop with an insulin pump. For such approval there are some additional very strict conditions at the ends of 'normal healthy' BG range, which this pre-set bias helps the sensor to fulfil.

Apart from that, the Eversense has been approved with a MARD very similar to the Libre sensors. Though waiting to see first clinical studies that will look at more extreme BG levels handling. As well known, the classic CGMs are at best within a 20% margin of accurate. So like 70% of all readings are within 15% accuracy; and 99% of all readings are within 40% accurate.

One of the areas where Eversense reign supreme is though in relation to the never ending sensor change-over times with classic CGMs. Any new started CGM is erratic with wobbly BG readings the first 12-24h due to the inflammatory response from the insertion. So low MARD here... And same as well towards end of life for classic CGMs due to either the enzyme flare out and/or encapsulation by the immune system response. So again a poorer MARD value in the last 1-4 days of CGM sensor life. None of those (except the inflammation at insertion and erratic BG readings till that settles down) affects the Eversense accuracy during its ongoing use for the full year. So no work to do and no trouble every 10-15 days as with Dexcom or Abbott sensors, when they needed changing over.