Is there a group of people that CGM just doesn’t work?

[Jollymon]

I’m wondering if there’s a group of people that cgm just doesn’t work. I’m on a 4th CGM system and am just not impressed with it. The numbers don’t match. The delay is crazy. Sometimes it just seems to do its own thing. I’m wondering if I’m just in a group that should not attempt to use these things. Maybe I’m just expecting more of these things that they can produce.

CGM said my bs was in the tanks all afternoon. My meter said I was fine. Every time I looked at the cgm I was tempted to correct, but my meter said to do nothing. So I did nothing, and I was fine.

If I’m only supposed to look at it for trending, my trends are good. From past experience I’ve leaned to not trust cgm, and today reinforced this. I’m just wondering if I’m in some kind of group-set that cgm just doesn’t work.

Today I did a tough drive in some really lousy weather. The roadway was an ice rink. I needed this cgm tool to work, and I just wasn’t impressed.

 

[Deleted Account]

Can you expand on what type of BGM you are using?
I have tried the G4 and Libre. Neither were overly accurate and I found they became less accurate when I exercised (which is a pain because that is when my BG changes most).
The G4 work me in the night with high BG alarms when I was only 6.4. The Libre once reported a 0.7 and I was alert to see it.
I have found the Libre more accurate when calibrated against finger pricks using Glimp but still not always great.

What are your BGs like?
CGMs seem to be more accurate between 4 and 10. Higher or lower and they over/under report.

Finally, CGMs are inaccurate when pressure is applied which means night time readings could be much lower than reality.

My initial reaction to CGMs was the same as yours.
I am still incredibly nervous about dosing against one and I would not use the spot reading to determine if I could drive.
However, I find it useful for adjusting basal dose on my pump and noting when to bolus dose relative to food.
I guess I have had to calibrate my expectation.

 

[Knikki]

The problem is, that nothing is 100% accurate as said many times on the forum blood test meters only need to be some where between 15-20% accurate of lab tests, ALL CGM's work of interstitial fluid so will have a delay.

Some do get them that are very close to the bloods, however I find that outside there optimal range they can be fairly inaccurate.

They are good for "trends" indicating where you are going up or down BUT for me they never fully replace the finger prick meter even if they are not as accurate as you think.

 

[Jollymon]

I’m using Libre tight now. My doctors office set me up on a trial with it. In terms of trends, I think it’s good. I know I’ve got a solid basal rate. But for absolute numbers it’s off. Right now it tells me I’m 44, and my meter says 86. It drew a lovely flat line all night all in the red.

I’v also been on medtronic’s cgm in the past, and then dexcom’s G4 and G5. All work about the same for me- not very good. Medtronic said I over-calibrated their system but I just wanted it to be more accurate.

 

[Jollymon]

The problem is, that nothing is 100% accurate as said many times on the forum blood test meters only need to be some where between 15-20% accurate of lab tests, ALL CGM's work of interstitial fluid so will have a delay.

Some do get them that are very close to the bloods, however I find that outside there optimal range they can be fairly inaccurate.

They are good for "trends" indicating where you are going up or down BUT for me they never fully replace the finger prick meter even if they are not as accurate as you think.

Inserstial fluid isn’t blood glucose. But yesterday I neeed this thing to be more reliable in the tough drive through the ice. It just wasn’t there.

I’ll flip the receiver over and call the toll free number on the back. See what those people say about it.

 

[Jollymon]

Shelving the device and moving on.

The freestyle people, who were quite nice today, questioned my activity level and working it in the cold. If the device can’t keep up with what I want to do, just let it go.