LifeAfterDx--Diabetes Uncensored

A internet journal from one of the first T1 Diabetics to use continuous glucose monitoring. Copyright 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016

My Photo
Location: New Mexico, United States

Hi! I’m William “Lee” Dubois (called either Wil or Lee, depending what part of the internet you’re on). I’m a diabetes columnist and the author of four books about diabetes that have collectively won 16 national and international book awards. (Hey, if you can’t brag about yourself on your own blog, where can you??) I have the great good fortune to pen the edgy Dear Abby-style advice column every Saturday at Diabetes Mine; write the Diabetes Simplified column for dLife; and am one of the ShareCare diabetes experts. My work also appears in Diabetic Living and Diabetes Self-Management magazines. In addition to writing, I’ve spent the last half-dozen years running the diabetes education program for a rural non-profit clinic in the mountains of New Mexico. Don’t worry, I’ll get some rest after the cure. LifeAfterDx is my personal home base, where I get to say what and how I feel about diabetes and… you know… life, free from the red pens of editors (all of whom I adore, of course!).

Sunday, April 01, 2012

Four percent of the time your test strips are fully capable of killing you

I wish this were an April Fool’s Day post, but it’s not. Yesterday I told you to brew coffee. Today, break out the whiskey.

The food for the UltraLink is the current generation of OneTouch strips, the so-called Ultra Blue. Each strip tests the sample twice and averages the result. At least that’s what the TV commercials say, so it must be true. Checking the package insert, I couldn’t find anything about that, but I did see that you can use the strips up to 10,000 feet in altitude. They think. They actually only tested them up to 5,280 feet and “simulated” altitudes up to 10,000. I’m not sure how you simulate an altitude. Anyway, mountain climbers beware.

And if your hematocrit is off you’ll get false highs or lows. And if you take a shit-load of vitamin C or acetaminophen it’ll fuck up your readings. And if you need oxygen expect false low results, too.

On the bright side, your cholesterol can be up to 700 without effecting your results. So you’ll get accurate BGL readings right up to the moment you have a heart attack.

The official accuracy data for the strips shows an average of 2.5% variance strip-to-strip; with about half the strips within 5mg/dl of lab readings when below 75, and eighty-four and-a-half percent within 10 mg/dL. They claim 100% of the readings are within 15mg/dL at readings below 75. Still, that’s telling us that when we’re below 75 more than 15 tests out of a hundred could be off by up to 15 mg/dL. For perspective, if you were at 50 your meter might say you were at 65. Or 35.

How comfortable does that make you feel?

Above 75 mg/dL, the industry standard is to look at how far off a reading is from a lab test in percentage terms, rather than in mg/dL points. The Ultra Blue package insert shows that 38% of the strips clock in within 5% of a lab test.

68% of the strips are within 10% of the truth.

88.2% of the strips are within 15% of the truth.

And finally, 95.7% of the strips are within 20% of the truth.

Mind you, at a blood sugar of, say 250 mg/dL, 20% gives you an answer anywhere between 200-300. And don’t forget that 4.3% of your strips can’t even manage to be that good. Four tests out of a hundred, you should expect to be more than 20% off. And these are the strips you’ll use to calibrate your CGM. These are the strips you’ll use to decide how much insulin to take. What if your blood sugar is 350 mg/dL and you need to take a correction? What if you used one of those four-in-a-hundred strips that was more than 20% off? Your meter might tell you your blood sugar was 438 mg/dL rather than 350.

Well, at least they had the balls to put the data in every box of strips for anyone that wants to read them. Oh. Wait a minute. No they didn’t. The FDA made them do it.

By comparison, the cheaper-at-the-pump AgaMatrix Presto strips are much better with 95% of readings within 10 mg/dL below 75 (eleven and a half percent better performance); and above 75 mg/dL:

93% of the strips are within 10% of the truth.

97% within 15% of the truth.

And fully all of them never beyond 20%.

Maybe Med-T should be talking to AgaMatrix. Oh wait. Never mind. Too late. They’re already in bed with Bayer, rolling out the clunky old-fashioned and miserably inaccurate Contour meter as the next gen meter that will come with Med-T pumps. Contour is already the linked meter in Europe, and no doubt coming our way as soon as whatever contract Med-T has with OneTouch expires. The Contour was a good meter in its day. A decade ago. I find it lacking compared to today’s other choices, and I’ve never been impressed by the strip performance, at least not in that meter. (Oddly, the same strip preforms better in the cute-as-a-button Bayer USB meter. Presumably, the algorithms under the hood massage the raw data from the strip in a different way.)

It’s possible that the link-to-pump version of the old Contour might have a new engine under the hood, but here we’re back to a big, old-fashioned, clunk-a-mundo meter for our slim and sexy pumps. Groan.

Medical device companies still have a long way to go when it comes to giving us gear that fits into our lives and sings to our souls.

I wish Med-T would stop taking all these different ugly girls to the prom. Med-T makes their own gear (pumps, CGMs, mySentry, transmitters, inserters, and more); supplies (infusion sets, cartridges, sensors); and software. Why the fuck aren’t they just making their own meter and test strips??? I’ve met a number of Northridge’s geniuses. Even if making a new meter was rocket science, they’re more than up to the task.

Now, over time, various pump makers had dealt with the issue of BG meters differently. The old CoZmo had a strap-on (OK, it was more of a click on) FreeStlye meter that fit over the back of the pump and sent BGL data to the pump via the infrared ports on the meter. This BGL meter, called the CozMontior, was acutally a miracle of smallness, being about the size of a pack of Wrigley’s gum, and maybe only a quarter of an inch thick. But it did make an already thick pump miserably thick. Oh, and I just received an obituary in the mail from Smith’s Medical letting me know that the strips for the CozMonitor are now extinct. Once you run out, you’re screwed.

The death spiral of the CoZmo pump continues to steepen.

One of the newer members of the pump market club is the OmniPod, and it has a built-in meter. Pretty slick, as now you don’t have to carry a separate meter. Why don’t all pump companies do that? Well, because if your meter is built in, you can kiss off water proofing. That’s OK for a tubeless pump. The Pod is water proof after all, maybe the remote controller doesn’t need to be. But to put a strip port on a tethered pump is asking for water-borne disasters that’ll wipe out an $8K pump.

Animas is using the same meter Med-T is, with the addition of a few extra buttons that allows the meter to function as a remote, as well. Well, at least in theory. In practice, it takes so many extra button clicks as to not be worth it.

That said, I’m getting used to the UltraLink and there are some things I’m beginning to like about it. I still really hate the large size, but it is comfortable in the hand, and with my smaller belt case, I find it easy enough to carry with me. But what I really like is the way it talks to Revel.

The UltraLink meter talks to the pump in the same 900+ MHz language that the pump uses to talk to the mySentry monitor. Now, my old CoZmo had the meter that talked to the pump, but my insurance long ago refused to pay for the strips it needed. I’ve been using a Presto for several years, which requires me to manually enter BG numbers into the pump if I’m going to take a correction—which of course means I can’t be bothered to unless the shit is really hitting the fan. Let’s face it, it’s a hassle. But with UltraLink, every time I check my blood sugar, the numbers are magically transferred to the pump; and the pump helpfully asks me if I’d like to correct my blood sugar. Sure. Why not? Even if I’m only a hair above target, I’ll go ahead and do it, because it’s so simple to do. It’s just an extra button click. Effortless, really.

I expect this will acutally improve my A1C during my two month trail. We’ll see, I promise to share my before and after numbers with you at the end.

And I do like the fact I can link more than one meter to my pump. Somewhere along the line someone gave me an UltraLink meter for some reason, and it’s been hot-glued to my office wall at the clinic, as part of my meter lineup. I pried it off the wall with a screw driver, changed the batteries, and linked it to my loaner Revel pump along with the meter that came with the pump..

This lets me have a belt meter and a nightstand meter. Both meters beam their data to the pump. I’ve always had a really hard time with commitment when it comes to having a relationship with a single meter, so I’m glad Med-T has set it up so that my pump can have a ménage á trois with multiple meters. Well, more than an ménage á trois, Revel can have a wireless orgy. You can link up to three UltraLink meters to the pump (or Old BD Paradigm Link Meters), along with the Sentry, up to three separate remote controls, and God only knows what other devices that are being developed in the basement at Northridge.

I guess the only other thing worth mentioning about the UltraLink is its baby sister: the OneTouch UltraMini; the sexy little pencil-like blood glucose monitor introduced a few years ago. It doesn’t talk to the pump, or anyone else for that matter. But it’s small, sleek, portable, and cute as a button. As it shares strips with the UltraLink, it’s a great backup meter for pumpers. And unlike UltraLink, the Mini comes in a wide range of sexy colors.

But on a bad day, 4 times out of 100 tests, it can still kill you.

No April Fool’s.


Blogger Scott E said...

There's one more thing the UltraLink has going for it: it uses the same AAA battery that the pump uses. So, when your meter battery dies at the worst possible time, you've already got a spare lying around (hopefully). All the other meters use those expensive and hard-to-find button/disc/watch batteries -- which I never change because it's easier to go out and get another free meter.

8:15 PM  
Blogger Dougs ramblings said...

im another one mourning the decline of smiths and the cozmonitor ... I intend to ignore the warnings and use the cozmonitor with the new fangled strips until it dies or someone else realizes I dont want o cart around a purse worth of crap with me ... especially since I dont have the right chromosomes for that

7:16 AM  

Post a Comment

<< Home