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How much is normal for the Dexcom to be off from the BG meter? I just started my very first sensor yesterday so I am still in the first 24hours, but it seems like the sensor readings are 20 points or more off of my meter results. Does it help to continue entering meter readings to the dexcom to help it be more accurate? Or should I just do the 2 per day and hope the accuracy improves? Any help is greatly appreciated.

Laramie, WY

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"If the sensor is off by 100% up or 50% down (particularly more than once), call Dexcom and get a (free) replacement."

Really? Dexcom has this sort of policy? I thought they only do the once that give "Sensor failed" messages?

Another question regarding this Dexcom replacement policy. (I live in Europe currently). Do they want to have the old sensors back and the data before they give you refund in US?
I've had a few sensors replaced with no problem because they were way off. They send a new sensor (or 2), not a refund. They don't want the old sensor back, but sometimes ask that you send them data from your downloads.
Really? Wow. I need to send "broken" sensors back for "inspection" and the data before any discussion about possible sensor replacement... I do wonder why such a difference in the policy.
How close are your initial two startup BG values? That alone was an eye opener to me: the meter itself is not as perfect as you might think. Even so, you really should be thinking in terms of percentages and not values. 20 points is not a big deal when it's 240 versus 260 but 60 versus 80 might be. To me even 60 versus 80 isn't a big deal. It just means that I'm on the low side of normal and might want to eat something before long. The trend is far more important to me. Always think to yourself : Does this value make sense? If the Dexcom is clearly showing a drop then it makes sense that the meter might show a lower value than what the Dexcom currently shows because of the slight delay between blood glucose and interstitial fluid glucose. Likewise, if you're moving up then the meter might likely show a higher value.

I think I'm more fortunate than most here. The only time I see accuracy problems is at the very end of a sensor's life. By comparing calibration values to what the Dexcom reads at calibration time I find that on average the Dexcom is within 8% of the meter. Keep in mind that both the Dexcom and the meter have a margin of error so there's no such thing as perfect accuracy.

By the way, I'm now on day 28 of my current sensor and will restart it again soon. This is the longest I've ever gone.
Thanks for the info. The first 2 calibration readings were about 4 points off. It seems to be doing ok now, withing a few points of my meter. Guess it takes a day or so to level out.

WOW! 28 days. Thant is amazing. I plan on restarting my sensor once the 7 days are up, but how do you tell when it has come to the end of it's life?
Usually if I get an Error #1 or a ??? after 7 days it's time to change.
For me the curve becomes somewhat erratic towards the end of the sensor life. By that I mean that there are outlying values. I just took a picture of mine - once again this on day 28 - and I'm just now starting to see what will likely get worse in the next day or two. I don't know how well this will show up in the picture but I've added some arrows showing a couple of the values that are not consistent with where they should be.
How to tell when end of sensor life -

when there are 6 hours left, you will get an alert saying 6 hrs. Again at 2 hrs and 30 min. At 0, it will alert End of sensor. Then you just need to enter Start new sensor.

You can either wait for that, or restart at your own convenience. Before it expires, just select Stop Sensor. Then immediately select Start new sensor. It will repeat the 2 hours 'blank screen', and then ask for 2 BGs again.

If you can't remember when you started it, you can download to DM3 and check.
Wow Mike, 28 days is fantastic! Mine just failed last night at 10 days. Where do you have it?
I just stick with the recommended abdomen and alternate between sides. Based on recommendations on this site I also add a small strip of Flexifix to the top edge once it starts peeling off which is usually around the two-week mark.
may I ask if you sleep on your sides and if you get false lows at night?
I do sleep on my sides but I've not noticed false lows. Is the assumption here that sleeping on the sensor causes it to read lower than it should? What is your experience?




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