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If you use a CGM system that does not typically require calibration, have you ever been prompted by the system to calibrate your sensor? If so, how many sensors in the past 12 months have required a calibration?
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I use the 14 day FreeStyle Libre by Abbott. I am very pleased with wearing a CGM that I can use anywhere anytime. However, the accuracy is the biggest problem with this system and my sensors have to be changed before 14 days when they start reading LOW consistantly. My A1C has gone up instead of down because of this inaccuracy!
I do a finger check whenever my Dexcom G6 reading appears strange to me, and about half the time I find that it is way off, either too high or too low. One time, in fact, I started having an episode because it was showing something in the 70s when it was actually much lower. I love the convenience of having the G6, but I wish it was more reliable.
I have never been prompted to calibrate my Dexcom G6, but I do calibrate occasionally. This is almost exclusively during days 11-20 of wear (after restart).
If you restart a sensor, I would not trust it in the factory calibrate mode without verification, but rather do it in a calibrate mode. The system has been shown to start to deviate after 10 days, which is why it is a 10 day sensor. While it might work fine for some, I would not personally take the chance in factory calibration mode. Bad information can be worse than no information. A compromise is the calibrate mode, or doing fingersticks to make sure the data is valid, especially if using a hybrid closed loop like T-Slim w CIQ..
I think 2 options are missing: “My CGM sensor needs constant recalibration” e.g Minimed G3. And “I do t use CGM”.
I selected the N/A option.
I began using the Dexcom G6 in October 2020. It has never prompted me to calibrate. I have done several (less than 12) calibrations on my own in the intervening 15.5 months when my CGM was advising me I was low or high but I didn’t feel low or high and discovered that the CGM reading was off by greater than 20% from my finger-prick. I’m very pleased with the Dexcom G6 performance and general overall accuracy of its readings. I was dx’d Type 1 in 1976 and have been using the Tandem T:slim X2 with Control IQ, also since October 2020. I LOVE the combo of T:slim and Dexcom which has enhanced my control. I am in range between 92% and 98% of the time with this system. Mt previous control using an older medtronic pump was good but this is even better!
I answered 2 to 3 because I generally enter the code on my G6 and it rarely asks for calibration. However, I generally calibrate at least every couple of days because the sensor readings regularly vary from my glucometer. Sometimes by over a hundred points.
I use the Dexcom G6. It seems that whenever I have a high or Low BS, it tells me to test my blood sugar, which I don’t do. I wish Dexcom would delete that feature from their system. There is no need for the CGM to tell me that I had a high or low blood sugar two hours ago, please test my blood sugar. It’s too redundant and unnecessary. And, worst of all, it wakes me up after I have gone to bed, and have already made adjustments for the high or low BS.
I find that alarm so irritating too as it wakes me in the night as well.
If you are talking about the T-Slim pump w Dexcom and you get those alarms, those alerts are pump (not Dexcom CGM) alerts and can be and should be shut off. They serve no purpose for someone on a CGM. Alerts should be CGM based – what is my BG doing- not event based- I was high, remind me to do a fingerstick in 2 hr to verify I fixed it.
My sleep improved tremendously after I followed my CDE’s and Tandem rep’s advice to turn off all of the optional t:slim alarms and rely on my Dexcom alerts.
Honestly I’ve never had that happen since going to tSlim’s Control IQ.
The only time my dexcom said to recalibrate was when I tried calibrating and the number was too far off from what the sensor was reading. That happens rarely (a couple of times in three years) and has happened usually only on the first day. Since I no longer start my sensor till I have been wearing it for a day, I haven’t had that problem since I don’t remember when.
I said 2 or 3. I use the Dexcom G6, and rarely calibrate. Occasionally I get a welling up of blood when I place the sensor, and it invariably runs low, and is not fixable with calibration, because the fluid surrounding the sensor can’t equilibrate w blood glucose. When I see this, I just pull it- in past it would get into a seemingly endless loop of asking for more calibrations. I pull it and Dexcom replaces it. And I can get on with my life…
After my Dexcom sensor did that twice, I called Dexcom. They said they were aware of the issue and told me to wait 15 minutes after stopping a sensor and starting a new one. Haven’t had that happen again since starting to wait the 15 minutes.
This question is phrased incorrectly. I have NEVER been prompted by my Dexcom G6 to calibrate, even when it drops out as it does periodically. But I frequently do finger sticks to check its accuracy myself — at least once ever few days — and whenever I don’t feel as low as the G6 claims I am. I do two sticks, take the average, and then do two calibrations for force the receiver to accept my number. I often find the G6 nearly 20% off even when my glucose level has been flat for hours, so the reading should be complicated by the difference between blood and interstitial fluid. Moreover, I’ve found that the G6’s relationship to finger sticks is non-linear — it tends to read higher on highs, and lower on lows than the OneTouch test strips that I use. I don’t understand how Dexcom expects to use these sensors in a closed loop system. Frankly I felt more comfortable with the G5 and always got 14 days out of sensors, rather than the forced 10 of the G6. I’m also uncomfortable with how much waste plastic the G6 sensor applicator generates, although application is certainly comfortable.
Agreed with everything you said, which I had not read when I posted my comment. I would add that I quite often feel low, and the OneTouch will confirm that even when the G6 is still giving a reading well over 80, so it can be slow to alert to lows that should be reacted to. The reverse is true more often, though — the G6 saying I’m going low when the OneTouch says i’m still in an OK range.
I answered No because I do not believe my Dexcom G6 has ever prompted me to calibrate; but I still use standard glucometer test strips before each meal (I think its accuracy is probably better than the G6), and if it is more than about 15% different from the G6 (15 mg/ml under 100) I calibrate — that probably averages a bit less than once a day (often multiple times in one day, then many days without calibration).
Yes, I use Dexcom G6 and it’s been a really annoying issue this year. They replace the sensors when I call, and I mostly just ignore the prompts. But lately almost every sensor has asked for calibration.
The last call I made I was told it’s because I have a new iPhone, but it started before that.
I use medtronic. We calibrate.
the libre 2 has occasionally suggested that I confirm with a meter.
I have never been prompted by the system to calibrate, but each time I change my sensor I have to calibrate because I have significant variances during the first 4 or 5 hours of a new or restarted sensor.
I figure I’ll have sensor data off for up to 48 hrs. Sometimes it is onl for 24 hrs.
same here. I always check after I insert a new sensor. Sometimes I don’t need to calibrate, but I’d say half of the times, I do. (Dexcom G6)
After bathing (I love my hot bath) my sensor numbers sometimes are way off. I calibrate to get my numbers more in range with my BG from finger stick because it takes too long for the readings to get normal again. On occasion when dex reading was off by a lot, it will come back and ask for a calibration. It will usually work itself out but it screws up my numbers without my having a chance to document in Clarity, why, for the record. I really don’t like not being able to write my own notes in Clarity. It would help me in problem solving.
My Dexcom 6 has never asked me to callibrate. I didn’t know it could. I calibrate every sensor at least once on my own initiative.
I’ve not been prompted by the system, but when I have thought the cgm numbers were inaccurate I have tested with a meter and then calibrated the cgm when necessary.
I can’t remember ever getting a calibrate alert with my G6. What I’ve found interesting interesting, since having a DAD, is the she alert’s me a good 10 to 20 minutes before my G6 does for lows and highs. She’s a heck of a lot more friendly , too.
6-8 sensors
I use Dexcom and it isn’t supposed to need calibration per Medicare so they don’t cover test strips. However, it does. How does one know if it is accurate if you don’t test?
I use a Tandem X1 with a Dex G6. Yes, I get prompted every time I have a High or low, by my Pump and Smart phone. However, it’s exactly what my Endo. and CDE also has suggested. But I have not found to many big differences to actually make the Calibration change. They have always been within the Strip, Sensor and Tester tolerances.
I agree with Lawrence S. But there’s always a time when a calibration may to done. Sometimes twice.
I am asked every time to calibrate and I never do. The thing you need to remember about cgm data is the 20 minute lag time with interstitial fluid. A blood sugar meter is much more timely accurate however it is such a PITA. There can be wild differences when your blood sugar is moving up or down. I still won’t use a bs meter. When your trend is flat my cgm is very close to a bs meter. When rising or falling your cgm data is 20 minutes behind reality. Easy smeasy.
sweet charlie agrees with Don..
I answered No, but on 3 occasions I had to check my sugars 2 of the 3 my sugars were way off
I have never been required to calibrate. I will manually check as needed to compare for accuracy. It’s never been more than a few points difference.