Accuracy in Glucose Meters.
I've been diabetic for over twenty years, and when I was diagnosed in 1986, my first meter was an Accu-Chek (this post has some pictures of these old diabetes meters). The strips were large, absorptive pads that soaked up the blood drop and changed color after I wiped the blood away with a clean cotton ball. The color strips were either stuck into the machine and read after 120 seconds, or the color pads were compared against the guide on the side of the strip bottles.
Comparing colors? Total guessing game. But waaaaay back in 1986, glucose meters were FDA "OK'd" to be off by a margin of 20%. That means (if my math is right, and don't trust me that it is because I'm still a Morrone) if my meter said "100 mg/dl," I could have been anywhere between 80 mg/dl - 120 mg/dl. For me, particularly at this stage in my life, that's "almost low" or "almost needing a correction bolus."
Wouldn't you think we've come such a long way since then?
Oh, but we haven't.
The standards for glucose meter accuracy haven't been tightened up since before my diagnosis. Sure, meters have gotten fancier and faster and they come in a variety of brands, colors, and sizes, but they aren't more accurate than the ones I used when my fingers were being lanced for the very first times. (And this was proven to me when I was at the ER the other night - the nurse busted out a Lifescan meter that was older than dirt to test my blood sugar. It was their approved hospital meter, and the results were the same on that meter as they were on my current Lifescan meter.)
Scott wrote a remarkable post about the issue of meter accuracy yesterday (click here to read it) and Kelly also hit this nail squarely on the same day (her post can be found here). And Bennet questions what accuracy is in the first place. And after reading their posts, I'm inclined to comment as well.
I base EVERYTHING I do, diabetes-wise, on the information provided by my glucose meter. I base my insulin-to-carb rations on those results, my basal rates, my food intake, and my exercise decisions on those numbers. I calibrate my Dexcom using those numbers. EVERYTHING. Hell, maybe not even limited to just diabetes stuff. I won't get into my car and put the key in the ignition if my meter shows a result that's too low, and I am reluctant to eat more than a salad at dinner if my glucose result is way too high.
So when the numbers being provided by my meter aren't as accurate as my dedication and determination deserve? I get a little fired up.
Over the course of my diabetes life, I know my meter has thrown some wonky results. I'd have to ask my mom if she ever saw any crazy results, but I know since monitoring my own disease, I've seen plenty. Over the last fifteen years or so, I've used meters from Accu-Chek, Agamatrix, and Lifescan, and in the last few years, exclusively from Lifescan, due to what my insurance covered. And for the most part, I never second-checked any of my results, unless I really felt that they were "off" in accordance with my physical symptoms.
But since using the Dexcom, I've been double, and sometimes triple, checking results. Take, for example, the other day when I received the following results:
3:56 pm 86 mg/dl
3:57 pm 159 mg/dl
3:58 pm 164 mg/dl
The only reason I double-checked that first result was because the Dexcom had me at 170 mg/dl, not 80-ish. I know the CGM isn't for dosing or treating, but it's pretty friendly for trending and "gisting," so the discrepancy caused me to double-check the result. And, for the record, my hands were freshly washed with soap, dried, and clean. The lancet was new (I know - dumb luck on that one). And I wasn't eating or exercising at the time. So what gives? 86 and 164 are very different numbers. That's waaaaay more than 20%. Even I can do that math.
5:51 pm 110 mg/dl
5:51 pm 203 mg/dl
5:51 pm 229 mg/dl
This is not the first time this sort of thing has happened - I've blogged about it before and have linked to several of those posts throughout this post. But now, things are different. I'm in a constant state of blood sugar panic these days, worrying that not only are these results (accurate or otherwise) affecting my health, but how are they impacting my currently-being-built baby? Would I be double-checking these results if I wasn't pregnant? If I wasn't worried about BSparl, would I be willing to use three test strips (aka almost $3.00) per glucose check per sitting?
The FDA recently had meetings about this very topic: glucose meter accuracy. (CWD mom Ellen Ullman actually spoke at this meeting, representing the diabetes community. Go Ellen!!) And Scott had an excellent synopsis of one of the most disturbing statements made at this meeting:
Not good enough for me. I'm expected to maintain an A1C of 6.5% (or less) throughout my pregnancy. Diabetes complications, no matter how hard we work to advocate against the guilt, are still ascribed to the patient, not the disease.
I'm working very hard to take care of my diabetes, and to have my efforts impacted by industry apathy isn't right.
To echo Scott's call to action, I'm urging us all, as members of this influential diabetes community, to visit www.regulations.gov and search for Docket No. FDA-2009-N-0604 to leave your comments. Tell the FDA that 20% isn't good enough, and we deserve every chance to take the best care of ourselves.
I don't care if my meter comes in 15 different colors and can juggle knives - it needs to be ACCURATE.
Raise your voice.