HbA1c units changing 1 Oct

[benedict]

Hi all, on 1 October 2011, the units for measuring HbA1c numbers are set to change from the % value that a lot of us are used to to mmol/mol.

As an example - an HbA1c value of 6.5% is 48 mmol/mol in the new measurement.

The conversion is a bit complicated for most of us so we've got a calculator that will do the conversion work for you.

Use the conversion calculator here
http://www.diabetes.co.uk/hba1c-units-converter.html

[borofergie]

Thank you Benedict.

Is there any chance you could increase the precision level of the calculator?

When coverting from mmol/mol to % (as many of us will have to when we get our HbA1c results) I get the following:
37 mmol/mol = 5%
38 mmol/mol = 6%
39 mmol/mol = 6%
40 mmol/mol = 6%
41 mmol/mol = 6%
42 mmol/mol = 6%
43 mmol/mol = 6%
44 mmol/mol = 6%
45 mmol/mol = 6%
46 mmol/mol = 6%
47 mmol/mol = 6%
48 mmol/mol = 7%

There is a big difference between 47 mmol/mol and 38 mmol/mol but according to this calculator they are all worth a 6% in old money.

I'm not being deliberately predantic, but since many of us fight for every 0.1% reduction in HbA1c, this makes a confusing change even more confusing.

[benedict]

Oh cripes, that's no good at all. Thanks borofergie.

Give us a day or two and this should be fixed.

[Administrator]

Hi guys - glad to say it's fixed - giving results to 4 decimal places.

[borofergie]

Hi guys - glad to say it's fixed - giving results to 4 decimal places.

I just noticed. Thanks Benedict! It's too accurate now

[johnny37]

Dont know why anyone would want to know to one ten thousandth (4 decimal places)!

I noticed that each increase or decrease (0.1%) on the HBA1c scale is worth (with rounding) 1.1 points on the new scale.

6.0 = 42
6.1 = 43.1
6.2 = 44.2

and so on.

Yeah, I know that this theory is going to lose a decimal point somewhere eventually but it comes back again on the next number. hey ho!

[ursus262]

The question I would ask is this: why?

They've always got to fiddle around and tinker, haven't they. Managing the condition is hard enough without the medical profession making it more complicated.

[Grazer]

Bet we all convert back to % and report on here in that number for ages to come!

[noblehead]

I'll always ask for it in %, after 30 years I'm not going to change

[PHARMANCO]

Forget HbA1c value as a %
Accept the new mmol value.

Benefits: mmol will allow you to detect smaller ups and downs that would not show up in the % value.

[borofergie]

Forget HbA1c value as a %
Accept the new mmol value.

Benefits: mmol will allow you to detect smaller ups and downs that would not show up in the % value.

Ummmmm. I doubt it. The accuracy of the tests is the same, no matter what units, you're probably just observing rounding errors.

[joppie230261]

I agree with Noblehead. A % figure is something you can visualise where a reading of mmol is basically meaningless at first glance. How many people remember how much a mole is from their chemistry at school?

[IanD]

I agree with Noblehead. A % figure is something you can visualise where a reading of mmol is basically meaningless at first glance. How many people remember how much a mole is from their chemistry at school?

Welcome to the club no-one wants to join

I too agree. We can relate % directly to our finger-prick measurements (even though it is a different measurement), whereas the new figure is alien. I suspect it is an attempt to restrict info, rather than inform, so that we are increasingly in the hands of the health professionals.

Happily our hospital returns both units still. It's only an extra line on the computer that takes no effort on their part, but gives us useful info.

[finntasticemma]

I am quite confused now. My diabetic nurse has always told me my HbA1c in mmols. She recently told me it as a percentage and I was very confused. I think that a consistent approach is needed!

[phoenix]

I too agree. We can relate % directly to our finger-prick measurements (even though it is a different measurement), whereas the new figure is alien. I suspect it is an attempt to restrict info, rather than inform, so that we are increasingly in the hands of the health professionals.

Britain is part of the world and it is the result of an International agreement. The changes are to reflect improvements in modern testing and to ensure international standardisation. New methods meant that the percentages given were not really accurate reflections .
http://www.ngsp.org/ifccngsp.asp
On top of that parts of the world including some parts of Scandanavia and Japan used methods that meant that their HbA1cs were not at all the same as those used elsewhere .(eg the Swedish Mono S HbA1c reads about 1% lower than the DCCT HbA1c formerly used in the UK and other parts of the world;)
Imagine the confusion that could cause when a person from Sweden moved to the UK
All HbA1c methods will now give the same result in the same units no matter where in the world the analysis is performed.

I cannot see why you think that there is an to restrict info anywhere; convertors are freely available in many places including the DUK website.
Here is a Swedish one, explaining the differences to that population. (note they have been using the new units for over 2 years now)
http://www.hba1c.nu/english.htm

There is also a proposal to also give estimated average glucose levels to patients . This hasn't been implemented in most countries (including the UK). There is some concern that these figures may not apply to all groups so countries like the UK are awaiting the results of further trials.

I think that the change may be beneficial in those countries such as the UK that use mmol/l There were people that did seem to equate their meter readings with their HbA1cs and of course they were not equivalent at all.
An HbA1c of say 5.7% is the equivalent of an estimated average glucose level of 6.5mmol/l (ie not an average in the 5s)
An HbA1c of 10% is the equivalent of an estimated average glucose of 13.4mmol/l (much more than an average of 10)


I live in a country where that type of confusion was never a possibility, my glucose is measured in mg/dl and the 5.7% reflects an average of 117mg/dl .

The new changes will affect all countries, some sooner than later.
It's just a new figure and eventually when they drop dual reporting people will get used to it, new people will never know the 'old' method.