Why Aidex shouldn’t be on a Formulary. Anywhere.

You may remember, back in the summer of 2022, the author of this site wore an Aidex system (distributed by GlucoRX in the UK) to try and find out how well it worked, and was wholly unimpressed on a lot of fronts.

That hasn’t stopped it from appearing on the England Prescription Drug Tariff where it is still, unfortunately, the cheapest offering, and still, in my view, the most unsafe.

Thankfully, since then, we’ve now got a full trial where the Aidex has been put through its paces alongside a Libre2 and a potential upcoming device. It contained 30 participants, all of whom had type 1 (twice the number in the original study used for approval), and let’s just say that, compared to the original trial which Microtech provided, the data is, ummm, putting it politely, “interesting”.

And safe to say, I feel vindicated in my views as to the safety of the Aidex. Take a look here for the full details.

The tawdry details

In brief, this is a horrible picture of a sensor that is highly unreliable and very inaccurate:

  • Only 48.4% survived for their expected 14 day life;
  • The reported overall MARD was 21.9% (to put that in context, it’s worse than Dexcom and Medtronic sensors from more than 15 years ago);
  • The reported MARD was split between new transmitter firmware (21.0%) and old (24.3%);
  • With calibration it only improved to 15.5%
  • At glucose levels below 70mg/dl (3.9mmol/l) it systematically displayed readings that were 7.9mg/dl (~0.5mmol/l) above this level;
  • In normal range, it showed a negative bias of 18.5%;
  • Sensor to sensor variability was incredibly poor with wide confidence intervals;
  • It struggled to detect high rates of change in values.

Not exactly a vote of confidence, and many of the findings reflect what my n=1 study suggested.

But perhaps more tellingly, in a study with 100% T1 participants, the Aidex appears to have been undone by glucose variability, which the original study, with only 12% T1D participants didn’t show.


As I’ve pointed mutliple times, the study make up and participation matters on topics like this, and this is a really good example where a product with a questionable reference study has crept under the radar to be nationally available to an unsuspecting public who have no idea of the issues that have been uncovered in subsequent work.

In England, the NHS BSA should be taking another look at what’s available, and given this data, removing the Aidex from the list of options.


  1. We started a number of FB user groups, both U.K. and international as this did look quite promising. Sadly we had the same results as you and so have most of our members (though not those financially involved) Our results were documented in those FB user groups. We fully agree with your conclusions.

  2. My experience of the device is a lot different from yours? As a user of the Aidex device I have found that it reads higher than finger prick tests out of the box so to speak. I spend a couple of days calibrating it when first applying and found that the readings are way within the 20% margin of error, in most instances not more than 1 mmol/L different.

    • I’m pleased it works for you. There are many people who have quite a different experience of the system.

      • Perhaps they are not calibrating theirs correctly? Anyhow, happy to put the case for the other side.

        • I’d suggest that when the manufacturer states on their website that “AIDEX calibration is optional”, and statements like “[Various technologies] were used to produce sensor batches with low variability. You don’t have to calibrate the AIDEXT CGMS with your meter.”, complaining about how a user calibrates the system is a bit of a dead-end argument.

          • Excuse me I didn’t complain, I asked a question. If you cannot tell the difference perhaps you would be suited to a role other than admin.
            This is my last comment here, unsubbing from updates now.

          • There are ways to ask questions, and passive-aggressive questions suggesting that the users were at fault is very much a complaint about the users, which of course would not be a problem if the system was supposed to be calibrated. But it’s not.

  3. Let’s be honest. This product is available currently because it is the least expensive cgm product for GPs to prescribe and integrated care systems to stomach in terms of depleting ICS’s budgets, particularly during a cost of living crisis when HM Treasury wants government departments to be frugal.

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