COMPARISON of the NUMERICAL and CLINICAL ACCURACY of FOUR CGMS

[Ellen]

Diabetes Care. 2008 Mar 13 [Epub ahead of print]

COMPARISON of the NUMERICAL and CLINICAL ACCURACY of FOUR CONTINUOUS GLUCOSE MONITORS.

Kovatchev B, Anderson S, Heinemann L, Clarke W.
University of Virginia, Charlottesville, Virginia, USA.
Objective: To compare the numerical and clinical accuracy of four continuous glucose monitors (CGM): Guardian(RT), DexCom(TM), Navigator(TM), and Glucoday(R). Research Design and Methods: Accuracy data for four CGM were collected in two studies: Study 1 enrolled 14 adults with Type 1 Diabetes (T1DM) at the University of Virginia (UVA); Study 2 enrolled 20 adults with T1DM at the PROFIL Institute for Metabolic Research, Neuss, Germany. All participants underwent hyperisulinemic clamps including 1.5-2 hours of maintained euglycemia at 5.6 mmol/l followed by descent into hypoglycemia, sustained hypoglycemia at 2.5 mmol/l for 30 minutes, and recovery. Reference blood glucose was sampled every 5 minutes. The UVA study tested simultaneously Guardian(RT), DexCom(TM), and Navigator(TM); the PROFIL study tested Glucoday(R). Results - Numerical accuracy: During euglycemia the mean absolute relative differences (MARD) of Guardian(RT), DexCom(TM), Navigator(TM), and Glucoday(R) were 15.2%, 21.2%, 15.3%, and 15.6% respectively. During hypoglycemia, the MARD were 16.1%, 21.5%, 10.3%, and 17.5% respectively. Clinical accuracy: Continuous Glucose Error-Grid Analysis (CG-EGA) revealed 98.9%, 98.3%, 98.6%, and 98.7% A+B-zone hits in euglycemia. During hypoglycemia, the A+B-zone hits were 84.4%, 97.0%, and 96.2% for Guardian(RT), Navigator(TM), and Glucoday(R) respectively. Due to frequent loss of sensitivity, there were insufficient hypoglycemic DexCom(TM) data to perform CG-EGA. Conclusions: The numerical accuracy of Guardian(RT), Navigator(TM), and Glucoday(R) was comparable, with advantage to the Navigator(TM) in hypoglycemia; the numerical errors of the DexCom(TM) were approximately 30% larger. The clinical accuracy of the four sensors was similar in euglycemia and was higher for the Navigator(TM) and Glucoday(R) in hypoglycemia.
PMID: 18339974 [PubMed - as supplied by publisher]

[Nancy in VA]

Thanks for this - confirms what I have been hearing that the Navigator is a bit more accurate for lows.

[KitKat]

Thank you but I still don't know how our children can deal with such a large (and what I hear) painful sensor.

[kiwikid]

Bless the people who volunteer (or otherwise)to be the participants in these trials. I realise that they are in a 'safe' enviroment for the trials, but it must be hard to allow yourself to be 'hypo' for sustained periods of time. Maybe they get a free CGM and free lifetime supplies for their trouble

[Budapest]

Thanks for the post.

Glucoday? Anyone more info?

[rickst29]

you've clipped an incomplete sniipet of javascript, not a URL. I found a couple of copies of this abstract, but is the whole article available anywhere? Thanks in advance.

[Ellen]

I copied the abstract from pubmed. I believe you need a subscription to access the full text for free, or click on pdf below and pay for the article. Alternatively, find the email address of the author and respectfully request a reprint :-)...works like a charm 99% of the time.

COMPARISON of the NUMERICAL and CLINICAL ACCURACY of FOUR CONTINUOUS GLUCOSE MONITORS
Boris Kovatchev, Stacey Anderson, Lutz Heinemann, and William Clarke
Diabetes Care published online on March 13, 2008 as 10.2337/dc07-2401 [Abstract] [PDF]
http://care.diabetesjournals.org/papbyrecent.shtml

[frizzyrazzy]

for any of you who have access to AKO (army knowledge online) you can get most journal articles for free. Don't ask me how , since AKO is a beast to navigate and it takes me about 20 minutes each time to find where they are...but they are there - somewhere in "my library"

[50years]

Does anyone know whether the comparison was done using the Dexcom Seven, which is a huge improvement over the older Dexcom STS? The results are consistent with my experience with the STS but inconsistent with my experience with the Seven. Given the less than 12 months the Seven has been available, the lead time for a study to be done, reviewed, and published, I suspect that the first generation STS may be the product tested. If anyone can access the full text for the abstract, please let us know.

[Twinklet]

The Navigator sensor insertion isn't painful per my 10-year-old. We do use LMX cream prior, though. The sensor platform and transmitter IS large, but not as big as the Omnipod. Remember how huge the first Minimed sensor was? Abbott will release a smaller transmitter size in the not-too-distant future.

We have no experience with other sensors, but so far the Navigator is SPOT ON with her BG checks. If she's in-flux, it does seem to be 10 minutes or so behind for hyperglycemia. However, it reads spot on for lows in the mid 60's.