Hi All - I have been using the Dexcom for about a week. Its not as accurate as I would have liked. Does anyone use a CGM that they feel is extremely accurate? In the middle of the night 2 nights in a row it said I was 50 but I was really 108 and 101. I think my insurance would cover another brand but I wanted to know if anyone had a better experience. I used the medtronic CGM at my doctor office for 3 days and I thought that seemed more accurate. Any thoughts?
I have the medtronic CGM myself and it is right on the mark for me with being off by about 5 to 10 points off.
I’ve used the Minimed CGM and am now on the Dexcom. Dex is much more accurate than the MM for me. I think the problem is with calibration - the Dex folks say you can calibrate when you’re rising or falling rapidly, but I don’t buy it. Since I’m in the habit of only calibrating when my blood sugar is stable (and will be for at least 15 more minutes), I usually do the same with the Dex. The one sensor I wore that I calibrated initially when my blood sugar wasn’t stable was a not-so-accurate sensor.
The dexcom seems very accurate during the day… Often times it is within 5 points of my meter. But sometimes it is like 25 points off. And the middle of the night has been way off.
I’ve heard other people struggle with their Dex readings being off in the middle of the night. They have mentioned that if they sleep on the sensor it gets messed up. I tried both the Dex and the Medtronic and the Dex was way more accurate for me. I have found that if I put the Dex sensor in an area with too much “fatty tissue” then the readings are not as accurate. It’s better of in an area with only a bit of extra padding.
Rich, I’ve had the same problem with my Dex CGM, but after speaking with my CDE, I understand what’s up. The trick is to do what Kimberly said and calibrate your CGM with your meter when your bg is going to be stable for the next following 15 - 20 minutes, while realizing that the CGM is not 100% accurate and can only give you an “idea” of your bg level, not an “exact” portrait. You might try calibrating in the middle of the night when your CGM is so far off to see if that helps with the calibration for you… but from what I understand, you should allow for a 10 - 15% error margin in the reading of the CGM and your meter at all times. Good luck - keep asking questions, and don’t give up! =)
If you calibrate like everyone is saying, you’ll have what you need in accuracy.
Remember that all CGM are somewhat inaccurate at the high and low ends of the scale, but you are using alerts to keep you from going there and you are seeing the directions the BG is going to help you learn to stay in your target zone.
Also remember that if the CGM says you’re going down below 70, your blood glucose is 15 minutes ahead of your CGM, and you need a blood test to treat accurately.
I use Minimed … the company advertises all the wonderful features & my 30 minute training was not enough. Calling the help line until I was familiar w/ most of the persons answering(!) reading the manual & taking notes from the helpline THEN comparing notes & trying to make informed choices has helped somewhat…CGM can be great when it is on track but can be a nightmare when not. One useful tip was to turn off alerts at night – I know: alerts are one reason we use CGM