I was made aware of a new FDA glucose guidance by Sten Westgard. Reading the guidance revealed that I’ve been vindicated. Here’s why.

I’ve been critical of ISO and CLSI glucose standards and have critiqued them in the literature (1-5). I’ve also advocated for better performance standards on CLSI subcommittees that I’ve led, such as EP21 (Total Error) and EP27 (Error Grids). But I was summarily kicked off those subcommittees.

Previously, FDA recommended that companies adhere to ISO glucose guidelines, but a sentence in the new FDA guidance is rather striking: FDA believes that the criteria set forth in the ISO 15197 standard do not adequately protect patients using BGMS devices in professional settings, and does not recommend using these criteria for BGMS devices.”

As one reads what the FDA does recommend, some things that I have published appear in one form or another, such as:

  1. The FDA guidance requires error limits on 100% of the data. (ISO and CLSI allow a certain percentage of the data to have unspecified errors).
  2. User error should not be eliminated – For example, FDA says: FDA recognizes that most study evaluations performed for pre-market submissions occur in idealized conditions, thereby potentially overestimating the total accuracy of the BGMS device, even when performed in the hands of the intended user. Nonetheless, it is important that you design your study to most accurately evaluate how the device will perform in the intended use population.”
  3. And to point #2 Testing should be performed by the intended POC (point of care) user (e.g., nurses, nurse assistants, etc.) to accurately reflect device performance in POC settings; at least 9 operators should participate in each study (capillary, venous, and arterial).” Readers may remember my recommendation that user error should not be excluded in EP21 was vigorously objected to by some subcommittee members.


  1. Krouwer JS. Wrong thinking about glucose standards. Clin Chem, 2010;56:874-875.
  2. Krouwer JS and Cembrowski GS. A review of standards and statistics used to describe blood glucose monitor performance. Journal of Diabetes Science and Technology, 2010;4:75-83.
  3. Krouwer JS and Cembrowski GS. Towards more complete specifications for acceptable analytical performance – a plea for error grid analysis. Clinical Chemistry and Laboratory Medicine, 2011;49:1127-1130.
  4. Krouwer JS. Why specifications for allowable glucose meter errors should include 100% of the data. Clinical Chemistry and Laboratory Medicine, 2013;51:1543-1544.
  5. Krouwer JS. The new glucose standard, PCCT12-A3 misses the mark. Journal of Diabetes Science and Technology, 2013;7:1400-1402.

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