I have read a very interesting article of the sugary Jedi, I put a link and copy and hit.He tells us about Mad and tells us about current systems and which one has less mad.
Very good information provided.The images have not been copied I advise you to take a look at the blog.
Education26 October, 2018
By Mard
Post contents: [hide]
1 Calibrate?So that?
2 The psychological function of calibration
3 The career for accuracy
4 I already have my favorite
5 The best is what best suits me
One of the variables that raises the most interest among patients with diabetes when they analyze the new interstitial measurement systems is their accuracy, measured by the famous Mard (average absolute relative difference).This value is measured in percentage and means what difference between the measurements of the system to be measured with respect to another reference system.The latter should be an instrument of precision with supposedly as perfect values (usually the YSI, Yellow Spring Instruments) is usually used.During a specific time, glycemia are measured with both devices in simultaneous shots and at the end all the faced measurements are compared, calculating in each couple of measurements the percentage difference.On that list of differences (whether up or down) an absolute mean is established.This is the famous Mard figure and in summary it indicates how close the measured system is with respect to the most perfect possible measurements.Therefore, a minor Mard, greater accuracy.
Calibrate?So that?
Traditionally, interstitial measurement systems have required whenever the system with a reference value is done periodically, which in the user's case is always their capillary meter.That association helped the sensor to continue calculating glycemia and not deviating.But the passage of time and technical perfection has caused the MRD to be reduced until it is positioned today in figures that exceed exactly those offered by the capillary meters with whom we have always calibrated these continuous systems.
MRD in continuous glucose meters
Who gives the most accurate figure, the capillary or the continuous meter?Calibrate makes no sense ...
A capillary measurement system must be governed by ISO 15197, which in its last review (15197: 2015) establishes that at least 95% of the glycemia results are within the error range of ± 15mg/dl forglucose & lt concentrations; 100mg/dl or within ± 15% for glucose concentrations ≥100 mg/dl with respect to the reference method.Therefore, the question is forced: does it make sense to calibrate a system with another that is more inaccurate?The answer to my judgment is a resounding.Today, I see absolutely illogical that we adjust an interstitial system guiding us through another theoretically imprecise capillary.In fact, as we can all see, the road is the elimination of calibration in these systems, something that ABBOTT began rightly with its free freestyle.It was an entire revolution, which they have subsequently followed in Dexcom with their current system;The G6.And to the rhythm to which we are improving these systems, within a very close period of time both Medtronic (with its new Enlite 3) and Roche (with its Eversese XL) will also eliminate this process that is called to disappear.
The psychological function of calibration
It must be said that interstitial technology initially raised some suspicion by not a few people.And the calibration was a kind of psychological balm that allowed us to know that "everything was under control" with that hypermodern gossip that seemed taken from a science fiction movie and that it wasAble to read blood glucose only by a kind of hair under the skin.Let's say people were calmer calibrating.But the years have passed.And the systems have improved significantly.To the point that that Mard to which I was referring to the beginning has fallen into picture and is already in some systems clearly below 10%, a sufficiently reliable value to make any therapeutic decision.Something that today already allowed both Abbott's free and Dexcom G5 and G6.And the progressive implementation of these systems in many people has made them lose that initial fear and has led them to trust more than the figure they offer thanks to their use and verification in their own skin that the measurements they give are reliable.Because in the day to day, a person with diabetes is not only guided by their devices, but also by their experience and their sensations.And it has been seeing that these systems measure and precisely measure.
For example, today I trust the figures that these systems provide than the capillary meter.In many cases the physical sensations are those that suck us whether a measurement is correct or not.And I have proven how in the day to day what usually indicate some of these interstitial systems agrees more with reality than what the capillary figure tells me.
The career for accuracy
But even being important, the companies that develop these products are aware that accuracy is not the only important variable to decide (or for the National Health System to finance them).Aspects such as the procedure, the sensor, the transmitter, the app, the simplicity, etc ... are also very important.But accuracy is still one of the main claims towards users.And we have entered a continuous improvement of these systems so that the MRD continues to go down and down.Today we already have a system that has officially passed to the "First Division" of accuracy under 10%;Specifically 9% in the Dexcom G6 (I discard the G5 because in my tests, the G6 is demonstrating to be well above).In the other group are the Eversese XL (11.6%), Freestyle Libre (11.4%) and the Enlite 2 of Medtronic (14.2%).You can see the figures in the following table.
Mard system
Enlite 2 Medtronic 14.2%
Free Freestyle Abbott 11.4%
Dexcom G6 9%
Eversese XL 11.6%
It should be noted that these Mard figures are not immovable, and fluctuate according to various conditions, such as days of use of the sensor, placement zone, and some more variable, so they should not be taken as absolute values.Likewise, we can vary significantly with each sensor that we put on: a different area of placement ... an incorrect technique ... a more or less "active" immune system protecting from that foreign body inserted that is the sensor ... so, becauseThere are many small details that can make a difference, the different studies that manufacturers are carrying out show that implementing small measures usually improve the MRD.For example, something as apparently harmless as a better inserter (in the case of dexcom G6 for example) that ensures and uniforms each and every one of the inserts is a measure that improves and systematizes the MRD in each and every one of the sensors placed.That is why I say that these official figures are those that must be indicated by law, but they are always relative.
In the case of Dexcom G6, a study published this year in Journal of Diabetes Science and Technology (1) analyzed MRD accuracy in the child and adolescent population with this sensor, and the result was an incredible 7.7%, a figureNot only is it good by itself, but even more considering in which critic Population Group has demonstrated that effectiveness.On the other hand, Abbott presented at EASDSeveral weeks ago its new free freestyle 2, with which it offers an improved Mard of 9.5% and 9.4% in adults and pediatric, respectively (2).And Roche has recently presented the Precise II study, in which Eversese's new Mard figure is 8.8% (3).
Therefore, if we made a Mard update according to the data of the last studies that are published (if any data is wrong, those mentioned can write to me and I will be happy to correct it), the thing would go right now as seen in the following table, although we must remember that these are not the official figures, but figures obtained in clinical studies that sometimes do not cover the general population.
Mard system
Enlite 3 Medtronic 8.7%
Free Freestyle 2 Abbott 9.5%
Dexcom G6 7.7%
EANSENSE XL 8.8%
In any case, we see how they are all about to lose from ten percent.Medtronic already has its new Enlite 3 sensor about to reach Spain and Abbott will also significantly improve your Mard of the free 2. Sometimes the figure is improved with small changes such as retaking the programming of the algorithms or perfecting an inserter so thatPlace the filament always in the right place.
Comparative McG transmitters size
As with mobile phones, we also have our favorite continuous meter.
I already have my favorite
During these years many people have been lucky enough to try some system.In some cases more than one.And it is curious how clear preferences have been created in many people.Not always grounded, they are a mixture between their own experience ... external references of related or known people ... information received or collected by the network ... image of the brand ... previous history of experiences with that brand ... in short, a whole mixture of criteria (manyof them subjective and/or personal) that have made him leaning for a system, to such an extent that in some cases we begin to see already phenomenon of “fanboy” in the world of diabetes technology, something unheard of and unthinkable so far.
What the hell is a fanboy?
It is a popular word and that although we could simply translate as 'Persona fan' actually refers to those who carry their preferences to the extreme.They love an irrational brand and defend it to ultranza above the others in many cases without objective criteria, to the point even to sometimes denigrate the competition (even with less reasons even than those who use to extol their preferred brand).Some more extreme cases sometimes become violent and defend the brand passionately if someone criticizes it openly, as if they were life.Some of the best -known fanboys are Apple's, defenders of all the machines created by the Cupertino company, whatever.
I have attended conversations on the network in which someone defends their favorite diabetes product and does so in an intense way that you immediately realize that it is better not to continue talking about the different existing technological alternatives because it is wasting time.What are the most frequent fanboys in the diabetic world?In my opinion, those of Dexcom.And the most vehemente?Without a doubt, those of the "Do It Yourself" community of artificial pancreas and Nightscout.This phenomenon of intensification in our preferences is curious, since we are talking about health technology products and not televisions, which make their marketing campaigns and touch our subconscious.But after all, as I have said sometimes, these technologies are used as we use a TV, and we end up creating our preferences, even without having tried other systems, in the same way that happens in the consumer market.
The best isWhat is best for me
I have already said many times that one of the most frequent questions that ask me for mail is that of “What system is better?”, Either referred to apps, insulin pumps or interstitial measurement system.And my answer is always the same: it depends on what you need.We are not in an offer in which first quality systems and low quality Chinese systems coexist.Everything we have available today has passed through a thousand and one phases of clinical tests and trials to validate and improve it.It has the latest technologies and is the most advanced thing that medical technology can offer us.But each without exception has its qualities;its benefits, its advantages and its inconveniences.Today I have talked about the famous Mard or accuracy, but such a system has another type of benefits that can make it more or less interesting for us, even in the most nimic details, such as the thickness of their sensor orIf the control app is more or less intuitive.It is about thoroughly analyzing its characteristics and seeing if it fits what I need.Although in not long this choice I fear that it will no longer be possible, once we stop buying them and enter the health systems of the autonomous communities.Public systems that we know do not always value what they owe.Or rather, they will not always weigh everything in the most appropriate way.The matter of the monies sends too much.In fact, today there is still a lot to have all type 1 in all Spain without exception we can have these financed systems.And not only that, but I can choose the one that best suits me and not the one imposed by the autonomic government on duty as a result of an unfair contest and that is mistakenly carried out for the sake of an alleged savings by mistakenly thinking about things such as for example such as for examplethat only having a brand will save money.But this is another issue ...
(1) "Performance of A Factory-Calibrated, Real-Timeus Glucose Monitoring System in Pediatric Participants With Type 1 Diabetes".John B. Welsh, MD, PHD1, Xiaohe Zhang, MS1, Sarah A. Puhr, PHD1, Terri Kang Johnson, PHD1, Tomas C. Walker, DNP, CDE1, Andrew K. Balo, Bs1, and David Price, MD1.Pubmed (external link in English).
(2) ABBOTT Symposium on Freestyle Free 2, EASD Berlin, October 2018. "Improved accuracy in the Flashle Freestyle Free Glucose Measurement System."Dr. Kristin Castorino.Sansum Diabetes Research Institute, United States.
(3) "A Prospective Multicenter Evaluation of the Accuracy of A Novel Implanted Continuous Glucose Sensor: Precise II".Christiansen MP1, Klaff LJ2, Brazg R2, Chang Ar3, Levy CJ4, Lam D4, Denham DS5, ATIEE G6, Winery BW7, Walters SJ8, Kelley L8, Bailey TS9.Pubmed (external link in English).
