To Care or Not to Care - "Severe Low %"

I’m finding that I’m becoming increasingly frustrated with trying to attain the elusive .4% Severe Low percentage. Why? Because that percentage is taken from Clarity and is based on the readings from the CGM…which just isn’t accurate more times than it’s not where lows are concerned. I would wager that at least 75% of the time when his CGM reads low, or severe low, he isn’t actually low or severely low. But these are the numbers the Endo use when we have our discussions. This past Endo visit I told them that this severe low % doesn’t mean much to me because it’s just not accurate.

I know there are some apps/tools (such as Tidepool) which supposedly merge the data to get a more holistic picture of what’s happening, but I’ve not found Tidepool personally helpful in figuring out any correct amount of ‘severe lows’ that Liam has actually been.

So the longer we live with this disease the less this number is meaning to me…

I still CARE about preventing ALL severe lows, but to actually come to a true and accurate percentage, in my view, just isn’t possible right now…until technology improves and the accuracy of the CGM are better for us, we have inaccurate CGM readings and only a small number of daily accurate finger-sticks to try to determine the percentage. Right now my percentage reads .8 for the past 90 days, but I would wager it’s more like .3, but I don’t know of a way to determine this for certain.

So, I’m stuck just not caring about that Clarity ‘severe low’ percentage because it’s an unrealistic goal to get that down to .4 or lower due to the nature of the CGM. Anyone else have this mindset? I’ve been trying to get under .4 for 3 years now and, because of the CGM inaccuracies, it’s falsely inflated to appear higher than it actually is.

I’ve started a notebook where I annotate each time he’s not low when the CGM actually reads that he is and I’ll use in the future in conversations, but it’s just depressing and frustrating and I feel like I’m banging my head against the wall trying to meet some percentage that keeps moving out further as the numbers continue being off for us.

Flip this around: you are reporting that Liam has minimal severe lows!! That’s awesome!!!

I have learned to double check those lows with a finger stick when I don’t feel them (shaking, anxiety, etc.) and also after treating a low when the G5 doesn’t start climbing back up. You are already teaching Liam this valuable approach!

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If you are worried, just copy this one and paste it over yours. I personally wouldn’t worry about it.

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I think your Endo is being overly worried about that severe low percentage and honestly I would just smile, nod and tune out when he chastises you at this point. Or you can bring a thick stack of papers showing that there’s a time lag, that Dex tends to overestimate the depth and duration of severe lows (by design!) and that there’s no data showing that time spent in severe low on CGM data is correlated to adverse outcomes (most adverse outcomes come from finger stick data and we just don’t have a great idea whether a person who has a handful of very low finger stick readings is low the same or more than a person with a CGM. I suspect it’s more though).

I’ve been trying to get severe lows down to 0 as well, but not at the expense of spending hours super high, which is what I’ve realized is what it would take for us. However, I have managed to get long stretches where he might be below 0.5% – and then there’s one day where he has a crappy time at school or whatever and that mucks up the percentage and he’s at 0.9%, etc.

Personally I’d focus on some other goals. Severe lows are sort of the outliers, so a few bad readings can skew the results, right? But I’d wager that “time spent low” below 70 mg/DL is a larger percentage of the time and that’s probably more representative of his true numbers than the severe low percentage. As such it might actually be a better indication of how much time Liam actually spends truly low. Focus on reducing that number if you are really keen to reduce all the severe lows --my guess is you’ll not get that severe low number to disappear on Clarity because it’s often an artifact. But if you see the regular old lows going down, that may help.

For what it’s worth, I’ve heard from people who were treated in Europe that they have much more aggressive targets there even for a child. I had one man from France tell me he was told by his endo that if he wasn’t having at least one dip below 55 a week that was a sign he wasn’t being aggressive enough in targeting normal blood sugar. Not sure I agree with that strategy either – but just so you know your endo is not really representative of all endo thinking everywhere

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This. 100%. One…crappy…day…can take it from .3 to .9 and it’s infuriating.

This isn’t really something I’m even talking about, though, that’s a negative that the Endo has brought up. They know we know what we’re doing and that we’re trying to prevent as many severe lows as we can. I guess this was more for me…I thought early on that this percentage was a way to gauge MY success or MY failure…but it’s not. If it were accurate data, yes to some extent…but it’s not. So it’s mostly ME being hard on myself and finally coming to the realization that this number (in our case) doesn’t mean squat. I’m just now finally realizing that and that’s the intent of this post was to figure out who else doesn’t really care about this percentage.

My three goals have always been as follows. Goal 1: Prevent as many severe lows as possible. Goal 2: Prevent as many PROLONGED highs as possible. Goal 3: Keep Liam’s A1C under 7%…and get it as low as we can get it WITHOUT sacrificing significant severe low periods to attain a lower A1C. I meet those 3 goals right now. The “severe low” percentage in Clarity is just chasing a ghost for us, or like charlie brown trying to kick the football only to have the football pulled up right before the kick…it’s just not possible because the numbers aren’t accurate, within Clarity due to the inherent nature of the CGM device.

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His regular low percentage, in Clarity is usually around 3%…1% less than the recommended 4%, so I feel good about it.

His regular low percentage, in Clarity is usually around 3%…1% less than the recommended 4%, so I feel good about it.

Yep, so Samson’s percentage low (<70) is usually about double that, and two-thirds of that time is spent between 60 and 70 mg/DL. And his “severe low” percentage ranges from 0.4 to 1% depending on if it’s a good or a bad two-week period. It’s usually around 0.7%. So I’d bet a ton that Liam’s is half of Samson’s severe low percentage; it just doesn’t make much sense that he’s spending so little time below 70 and yet almost a third of that time below 55.

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Most of the time…I would say 95% of the time, IF Liam goes below 60, it is for one or two ticks only. Most of his time is spent above 60 or 70.

I’m just going to stop beating myself up over that severe low percentage then. It’s just chasing ghosts for me. Like you said…one single crappy day and all the hard work is thrown down the toilet. That, combined with the inaccuracies of the CGM in the first place make 0% as you indicated, an artifact.

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Exactly. I don’t put a lot of stock in it. The number of times my Dex says I’m low and I test and I’m actually fine … or in the night I treat and then wake up higher than I want to be because I was never actually low. Or I DO briefly go low and treat and come up but the Dex says I’m still low for the next goldarn hour. The number is basically meaningless. The only way you’d get a more accurate idea of how much time he spends low is if you did a fingerstick every hour or half hour across 24 hours every day, and that’s not going to happen.

But if we don’t care about the “severe low” or “low” percentage, then we can’t care about the “high” percentage, which also means the “time in range” number isn’t real. Which means Clarity et al. are kinda pointless except for trends.

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Believe it or not, at least with Liam, when the Dexcom reads high, I would say over 50% of the time, possibly even 75% of the time, he actually IS truly high (according to a finger stick). It seems that, at least in our case, the inaccuracies are only relevant to lows and severe lows.

And believe it or not, this thread and conversation this may help us have a lower A1C in the future…I ride much higher than I tend to want too because of trying to hit this impossible goal. I am very conservative at times, but the CGM isn’t kind to me as a result, so this has opened my eyes to have even less fear about Diabetes…at least as far as it pertains to this data and the decisions I make based on the perceived past relevance of it.

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But if we don’t care about the “severe low” or “low” percentage, then we can’t care about the “high” percentage, which also means the “time in range” number isn’t real. Which means Clarity et al. are kinda pointless except for trends.

I don’t think that’s actually the case though. For us, time spent high is still pretty accurate. If he spends time above 300, that can be off by a fair bit (between 230 and 370). But when it says he’s over 200, he’s usually anywhere from 180 to 220. I think the issue is that the window on the low end of the range is much tighter. So for instance, being 15 points off can be the difference between being normoglycemic and critically low on the low end. I honestly do not care if Samson is 180 or 195; to me those are both high and treating them is essentially the same. Also we’ve found that when the numbers in the high range are off, they’re not off with a specific bias. They can be too high or too low but those tend to even out. But on the low end, by design, Dex really overestimates those lows, I think.

I also think that, since @ClaudnDaye is using G5 rather than G6, that’s another layer of potential error he’s working with. We’ve found G6, when it works, to be spot on almost all the time, despite its other annoyances. We found a lot more float in the numbers with G5.

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This is why I no longer let my docs office download my cgm. I discuss with them my own interpretation of issues or concerns I am having. If that includes a discussion of cgm data then I’d allow it. If it doesn’t, it doesn’t. You are paying them for the consult… if the cgm isn’t accurate and is giving them the wrong impressions, why give them the data?

i feel like the calculus is a little different with kids. I feel like it would raise red flags to an endo clinic if you didn’t allow them to see a kid’s numbers. I could be wrong though.

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Yeah, I feel the same way. I feel that, since he’s a minor and it’s a Doctor’s duty to protect life, that by not checking these numbers could put abusive parents in the position where they can keep the kid at severe low for 90% of the time and be killing their kids and the Endo not know about it. When he’s old enough, though, if he wants to do as @Sam recommended, I would be fully supportive. Right now, though, I am with you that I feel like it’s kind of an obligation as a parent to prove that I’m parenting correctly given the situation and I’m not trying to kill my child.

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I suppose it is different… but I’d still not let them forget that you’re the customer paying for their service. I’m often struck by how different it sounds like my relationships with doctors are than a lot of others’

This is actually something that’s causing me some anxiety… we’re moving to a much bigger city here soon where I’ll just be another random face/ patient that nobody has ever heard of. Will I be treated differently because I have no “standing” in the community when I go to see the doctor?

My Endo knows they work for me. Trust me. They know I understand Diabetes and I understand how to treat my child. I take their recommendations, though, and if they make sense I will follow their guidance. Unfortunately, I haven’t had any really good advice from any that I didn’t already know. But I am fast at calling BS when they say something that I know isn’t true, or isn’t true “for all diabetics.” Endos often think diabetes is a one-shoe-fits-all, and we all know that couldn’t be further from the truth.

Just this last visit, they presented their print-outs to me from Clarity (the severe low percentage graph especially). I sat them in the chair beside me and didn’t even look at them…instead, I said “These charts don’t mean anything to me. The data isn’t accurate and I don’t base any dosing decisions off of this data.”

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Me. Reports are only good while they are useful. When they stop being useful TO ME then I stop caring about them.

Not at all. You work for your child. Not for some report from Dexcom.

Likely your [new] community is too big for you to ever have “standing” in the community from an Endo perspective. My suggestion for your first Endo visit is to take a Valium and two shots of your preferred beverage before the visit. Chilax and get some perspective of where the Endo is coming from. If the Endo seems to have potential, next visit open up more and chat. If the Endo seems dumb as a stump then cut them loose and schedule next visit with a different one. Advantage of being in civilization :stuck_out_tongue: is there should be no shortage of Endos. Not like if you don’t like the first one, you would have to drive 642 miles to find another.

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I get what you’re saying. But if Clarity shows the amount of time low as taking up more space than it really does, that has to mean the next chunk – the in-range – is in reality smaller than Clarity shows. The difference has to be made up somewhere. And if two out of three aren’t accurate …

Of course, I speak as a G4 user. I can’t ever completely trust the thing.

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My endocrinologist wants my low percent (all lows, not just severe lows) at 4% or less. I’ve never been able to hit that. He doesn’t seem to worry about it except once when it was 16%. In my view, preventing severe lows that get really scary or require assistance from others is the goal. Lows, some lower than others, are just part of living with Type 1 diabetes. It’s the severe lows that get really scary that you really want to avoid, and it sounds like you are doing that.

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