The FDA is in the process of updating its final guidance on required accuracy of glucose meters and test strips, slightly tweaking a policy put in place in 2016 that tightened the scrutiny of these staple tools for managing diabetes.
While some may wonder about the need or significance of this at a time when continuous glucose monitors (CGMs) seem to be supplanting traditional fingerstick meters, the reality is that only a small percentage of PWDs (people with diabetes) are using CGM to date; it's unrealistic to think that traditional meters and test strips will disappear anytime soon. That means strip accuracy remains critical.
On Nov. 29, the FDA issuedupdated guidelines that lay out the standards for meters used in clinical settings and personal-use meters. There is a public comment period open through February 2019, after which the agency will review feedback before eventually issuing official, finalized rules.
Those who've been following this issue over the years may be experiencing déjà vu, from similar discussions and draft guidance published in early 2004 before the final rules came in October 2016. That was huge at the time, because accuracy rules hadn't changed in the USA since the 1990s!
Importantly, the new rules issued in 2016 applied to new products only, and did not impact meters and strips already on the market. So while these new tighter accuracy requirements were a positive change, our D-Community had to keep in mind that lots of less-accurate meters were still out there in the hands of people with diabetes. The current updates don't lay out any new ways to police existing meters per se, but they do suggest tactics to "close the gap between pre-market and post-market performance."
"Procedural Changes" to Meter Accuracy Rules
What was decided in 2016 remains mostly intact -- meaning these new November 2018 changes don't really improve the practical accuracy of our meters at home or in clinical settings.
Instead, we're told by the FDA that these newest changes are largely "procedural," addressing how manufacturers must keep track of their processes and the hoops they must go through in getting these meters and strips approved for market. The FDA tells these changes came at the specific request from industry players, who felt the 2016 document needed clarification.
"The changes to the both guidances included minor changes," said FDA press officer Stephanie Caccomo. "(Including) clarifying that sponsors should provide justifications for any data exclusions in their method comparison and user evaluation, removing specific examples of modifications and lot release criteria testing, and adding comparisons of the candidate device under test conditions to the candidate device at nominal conditions for certain studies."
In other words, aspects that don't translate to much for us in the D-Community using these products in our own diabetes management each day.
The earlier guidance put in place in 2016 on these two classes of products offered the most meaningful change --
For each, the accuracy standards require that blood sugar results fall within a certain percentage of the "reference method" for testing accuracy; they're only allowed to be so far off from the uber-accurate results provided by an in-laboratory glucose test.
FDA tells us they took broad feedback into consideration, to strike a compromise that would increase accuracy without creating too many roadblocks for industry.
"Based on feedback received from manufacturers, increasing the accuracy of these strips too much would increase their costs while reducing their availability to patients," FDA spokeswoman Stephanie Caccomo said. "Patient feedback indicated that they did not want reduced device usability (from increased testing time, increased sample volume, etc.) in order to maintain consistent pricing for strips where the accuracy has been increased substantially."
She added that "this represents a significant accuracy improvement compared to meters marketed even 5 years ago," yet FDA believes many of the meters already on the market today should be able meet these improved criteria too.
The specifics of those criteria are as follows:
Clinical Blood Glucose Monitoring Systems (BGMS) -
- 95% of values must be within +/-12% for blood sugars below or above 75 mg/dL
- 98% within +/- 15%
By comparison, the previous rules called for 15% and 20% accuracy across the board. In early 2014, the FDA had proposed tightening the strictest requirement to +/- 10%, but meter manufacturers and clinical healthcare providers objected because it could stop them from either making or obtaining meters affordably. So the regulators met in the middle at 12%.
The FDA spokeswoman tells us the reason for the discrepancy between the draft and final rules is "to balance the clinical needs in each population with the ability of the manufacturers to produce devices that meet these goals.”
Here is a link to the FDA's full 43-page guidance document for clinical meters.
Personal-Use Glucose Meters -
- 95% within +/- 15% across the measuring range
- 99% within +/- 20% across the measuring range
Comparatively, the prior rules called for 20% accuracy for most blood sugar ranges.
As of 2016, personal-use meters also need to carry "a prominent warning" that their test strips (which allow blood collection in an "open" environment) are not meant for use in clinical settings. This stems from long-standing concerns from both the FDA and Centers for Disease Control (CDC) about the risk of hepatitis B and other blood-borne diseases, and it's the main reason the agency split the rules into two different categories.
Here is a link to the FDA's 43-page document for home-use meters.
Other New BG Meter Requirements
Manufacturing Process: Beyond just the accuracy standard, the FDA also cracked down on manufacturers' lot release methodology — collecting information about manufacturers' sites and the quality of their production. This is accomplished through "data collection and site inspections," we're told.
Labeling: Perhaps most importantly, FDA has called for new labeling information on test strip vials; they must include information about the lot/production, and a description of the performance (accuracy data) on the outer box label so users can compare one meter to another.
Third-Party Test Strips: Importantly, the final rules add provisions specific to off-brand test strip makers that have come under criticism in recent years. While these strips are often less-expensive, they haven't been subject to the same requirements for accuracy as the meters -- particularly when certain brands are made overseas, and the FDA isn't able to inspect manufacturing facilities like they do in the US. Now, FDA rules say these manufacturers should "ensure that they are aware of any design changes to the meter because such changes could affect compatibility of the test strip with the meter." This must be addressed in the third-party company's 510(k) filing, and the FDA also recommends they submit the agreement documentation between the third-party strip maker and meter manufacturer.
"Post-Market Surveillance" of Glucose Meters
In its recent update, the FDA did not include any new aspects to examine meters and strips once they're on the market, aside from the general provisions and policies it already has in place for inspections and facility requirements.
But the agency is aware of the issue, and points to the new test strip lot criteria as a way to address post-market concerns. FDA recommends that, in their 510(k) submissions, manufacturers provide a description of the lot release criteria and a summary of the sampling scheme, which FDA plans to review as part of clearance.
"In an effort to close the gap between pre-market and post-market performance, and differences between test strip lots, test lot release criteria should be sufficient to ensure consistent quality of test strips. This will provide greater consistency across lots and across manufacturers, and a disincentive for poor post-market manufacturing decisions," according to spokeswoman Caccomo.
This has been a hot topic in recent years, leading to the emerging Diabetes Technology Society's surveillance program that is gaining steam now.
Compliance Is Voluntary?
No question that new guidelines for tighter accuracy are a good thing.
The trouble is that while medical products must be FDA approved to come to market in the US, these "guidelines" are not mandatory, but rather "non-binding," i.e. voluntary. This is because the FDA's policies state that its guidance is "not legally binding to a particular course of action... (but) still represents the agency's best advice on the matter at issue at the time they are rendered" -- presumably to protect the agency from getting embroiled in lawsuits.
Honestly, what's the point if manufacturers can just opt not to follow these new rules? We can only cross our fingers that market pressure will incentivize the vendors to comply. Despite the growing use of CGM and more automated D-tech, glucose meters and strips remain the "bread and butter" of diabetes management for the masses (so to speak), so ensuring accuracy remains important.