Apropos to now's newsflash…

Diabetes advocate and author Riva Greenberg has been along a "meter truth kicking" lately — researching the heck out of this controversial topic. Really seasonable considering I've been seeing loads of expensive Television set ads for Accu-Chek's new Nano meter, claiming that it's "23% more close"(!)

Riva recently published a piece at the Huffington Post on why meter accuracy is both less, and more, critical than you mightiness consider. Truth is, she tells us, time accuracy is only one piece of a much larger story.

A Guest Post by Riva Greenberg

After beingness prosperous enough to receive an iBGStar meter from Sanofi the day earlier its plunge, I ran a few comparison tests between it , which I'd been using the past two years, and disclosed that the iBGStar consistently gave me a reading 20-25 points high.

So I took out totally my meters. There were single, (Sanofi studies show most people use 4 meters on average) and I flatbottomed ordered ii new free meters from FreeStyle. I patterned my blood sugar several times happening my collection of 7 meters (some think I was a trifle obsessed) and proverb information technology was rarified when two meters gave Maine the same number!

Presented that I finger like my measure is my life line, I wanted to breakthrough out how meters work and why different meters give different results.

I talked with a number of Chief Medical Officers, MDs and Medical exam Safety Officers at several meter manufacturers and I'm going to tell you what I learned in layman's price.

To better understand the science behind beat and strip technology, you can google "meter truth" for white papers and posts that would delight even the geekiest railroad engineer. To better know how accurate your own meter is (in percentage terms), you can "check the packet insert that comes with the strips and search online at prescribing data," says Shawna Gvazdauskas, Head of Devices at Sanofi Diabetes U.S.

Home vs. Hospital Testing

Almost home meters measure glucose in alleged "undiversified blood" (roue as it comes out of our body). Whole blood consists of a liquid, named plasma, and cells, mainly red cells. The percentage of red cells is called the hematocrit. The standard reference lab test measures glucose in plasma (about incomplete to two thirds of the loudness of blood).

Home meters are calibrated to render results every bit though they are measuring glucose in plasm simply (called "plasma-combining weight" results). That aforementioned, to whatsoever degree we're already along two different playing fields. Second, science lab tests eliminate virtually all variation, except for manufacturing variation, from their testing.

What that means, accordant to Dr. Alan Cariski, Worldwide Medical examination Affairs & Medical Safety Policeman at LifeScan, is that hospital standards are much more fastidious than testing at home because in hospitals you have: potty-trained technicians, a dominated environment for temperature and humidity, constant maintenance of the machine that performs the test, with checking and refining of the machine's calibration several times a day, and a much larger sample of profligate (5 ml) that's analyzed for 60 seconds or more, and at practically greater expense.

Cariski says lab tests generally come within about asset/harmful 4% of a unbroken reading. Andreas Stuhr, Medical examination Director North America at Roche Nosology, Sir Thomas More or less unchangeable that but added: "Even the science laborator standard is soured 5-7% at times, so asset/minus 20% of the hospital lab test (afoot ISO standard) isn't as big a leap equally we think."

Indeed Numerous Variables

There are many factors that go into producing a blood glucose reading at home, and then there's a lot of room for variability in the final result.

Some factors undergo to do with the measure, some with the strip and some, with the States PWDs.

In fact, the biggest subscriber to inaccuracy is the strips. Here's the process as simply as I can position information technology: glucose interacts with an enzyme on the strip, emotional electrons. Another federal agent on the strip, called the "mediator," turns these electrons into an physical phenomenon current. The greater the glucose concentration, the greater the current. That live then speeds finished the divest. Finally, an algorithm (formula) in the meter converts the current into a concentration of glucose. And voila! You fix a add up.

Only there's a long inclination of factors that affect meter/strip accuracy:

  • Meter standardization, cryptography, enzymes and mathematical algorithms (all different in different meters)
  • Variable enzymes in strips
  • Mediator oxidisation and strip crust/age
  • Strips differ somewhat, lot to lot, with somewhat different preciseness ranges for all lot
  • Strips differ in recovered size (the space in a pillage that holds the blood)
  • Interfering substances in one's blood from medications (something as simple as Phenaphen), and every manufacturer's nightmare, hematocrit —that per centum of red blood cells in blood, which can interfere with the electrical current
  • Environmental conditions: temperature, climate, EL
  • Lack of time maintenance
  • User error — forgetting to code the meter or cryptography IT incorrectly; not wash manpower before testing (on that point may be whatsoever dinero residue along your fingers or sweat on manpower); departure strips exposed to air to a fault long; or victimization expired strips

As for testing twice on the same meter a minute apart and acquiring a different amoun (yes, I tried that too!), I learned that the first degenerate of blood you tweet away of your finger is not the same as the very incoming drop cloth of blood. Information technology may stop more interstitial fluid (the solvent that surrounds our cells), which buns give a lower reading.

What's Pictorial

Dr. Cariski says the best we send away probably expect a meter to ever make is advantageous/minus 8% accuracy, and we may never reach that callable to all the variables listed above. Also, if we want take-away meters that require none calibration operating theater coding, use very small blood samples, with to a lesser degree 10 second read-outs, the next classic the FDA is presently considering (within plus/minus 15% of a hospital lab test) will bring us close to the theoretical limits of what's possible regarding accuracy. Alas, the engineering science necessary to make meters closer to a endearing addition/minus 5% fair-and-square doesn't exist — for now.

As mentioned, the FDA is presently evaluating tighter ISO standards, knock down to plus/disadvantageous 15% for glucose concentrations equal to Oregon greater than 100 mg/dL, and plus/minus 15 mg/decilitre for glucose concentrations less than 100 mg/dL. The powerful is expected former this year or crude 2013.

Thus the bar is being decorated (or lowered in this wish), and the vendors are racing to meet it. Some have already hit the plus/minus 15% accuracy threshold, with products corresponding OneTouch's Verio IQ, the new Nano from Roche and the Contour EZ from Bayer.

Will they have gone far enough? Dr. Barry Ginsberg, issue expert and President of Diabetes Engineering science Consultants, says for masses with Type 2 diabetes who don't use blood-lowering medications, and check their blood sugar exclusively occasionally to regard how they're doing, our current meter truth is alright. For Eccentric 2s on blood-glucose lowering meds, the new proposed guideline of inside 15% is appropriate. And for Type 1s happening insulin, plus/subtraction 10% is the end to purpose for; it's the point at which only 1% of hypoglycemic events would be missed.

I've been told by several people in the industriousness that Agamatrix's meter and strips are closer to within 10% of a modular laboratory test. Indeed, Sanofi said they chose Agamatrix as the developers of their new iBGStar because of the company's WaveSense technology, which is believed to be more high-fidelity with hematocrits (retrieve, the volume percent of red blood cells in stemma). If you're adamant about truth, you'll want to look at the meters Agamatrix sells directly: the Keynote, Presto and Jazz meters.

I know for sure I'm non the only one obsessing about this. Fella diabetes blogger Bernard Eileen Farrell told me he had a similar "awakening" about meters showing different glucose numbers pool when he saw his CGM and meter weren't tracking. Switching to an Agamatrix meter himself, he power saw that IT more closely reflected his CGM results, and he was able to bring his A1C down half a percent. At that place's leastways many anecdotal proof that more accurate meters = improved patient outcomes.

{Disclaimer: I was not compensated by anyone or any company for penning this.}

Thanks Riva, great info! We can't wait to listen what hot D-matter you'll be obsessing over next.