Comment by lambda | Hacker News Reader

Comment by lambda | Hacker News Reader

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> It's the exact same hardware with artificial restrictions added to the software for unclear reasons.

Well, a quick search of Google Scholar turns up at least one citation in which the Freestyle Libre CGM was significantly less accurate in the first day of use than in later days, indicating that it needed more time for proper calibration:

https://www.liebertpub.com/doi/pdfplus/10.1089/dia.2014.0378

I expect that the differences are based on some actual findings, not just "unclear reasons," but you may have to do some research to find out.

The FDA is notoriously cautious, possibly somewhat excessively so, but there is some good reason for that caution; medication and medical devices can have unexpected behavior and side effects and it can take a lot of long term study to find them. One example of the caution working out well is the Thalidomide case, which was approved in many other jurisdictions but not in the US, and which had significant side effects on fetuses.

What's unclear is not the data but the decisions they made based on the data. Why is that first-day margin of error acceptable for European diabetics but not American ones?

Anecdotally, as a diabetic, the margin of error in that paper is much less scary than going 12 hours without a CGM. Poor data is much better than no data, especially if I know the data is going to be a little questionable the first day. I was completely ready to switch from Dexcom to the Libre until they announced that restriction.

> What's unclear is not the data but the decisions they made based on the data. Why is that first-day margin of error acceptable for European diabetics but not American ones?

The decisions were being made by different people. It's not like the FDA decided that Americans require a 12-hour window but Europeans only need 1. The FDA is just more cautious.

I wasn't being literal. The point is the FDA is overly cautious to the point that they're harming the health of patients. Slight deviations between the US and EU are understandable, 10x is questionable.

I'm sure there are people who would say that European regulators are being permissive to the point that they're harming the health of patients. A lot of women in the US could have benefited from thalidomide while it was being used in Europe, but the FDA was too cautious to allow it.

People will benefit from those extra 11 hours, but they'll also be hurt by the lower accuracy. It's completely reasonable for different people to weigh these costs and benefits differently.

> People will benefit from those extra 11 hours, but they'll also be hurt by the lower accuracy

11 hours without a CGM is a much greater risk than marginally lower accuracy. As a potential user of this system I've been unable to locate research to convince me otherwise.

Luckily there are other ways to get them, and the FDA's decision has kept you using a more accurate one.

> Why is that first-day margin of error acceptable for European diabetics but not American ones?

Because the FDA is very conservative, in part because that conservatism prevented the thalidomide incident back in the day.

When it comes to novel treatments, or monitoring devices, we don't know what we don't know. The FDA errs on the side of well-tested treatments and devices.

Extra inaccuracy during the first day could lead people to make mistakes that could prove dangerous or fatal. You don't have no data during the first 12 hours, you just have to fall back to the fingerstick method, which the FreeStyle Libre still supports.

It's possible that as more data is gathered in Europe and the US, it could be found that this extra inaccuracy is not harmful, and the European version approved in the US. Or it could be that the company is able to improve the device to improve accuracy in the first 12 hours, and get a new version approved.

It seems to me that other CGMs like the Dexcom require fingerstick calibration at lest twice a day, so I would think that 12 hours of having to use a fingerstick during calibration would be preferable to twice a day fingersticks.

Indeed the FDA is cautious. But we can also show the other way that inhibiting these technologies also has fatal results too.

What's the right regulation? I don't know.

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