Hi

I was also going to refer to this rather modest grading of the evidence and the lack of IFCC units, but I would like to make the additional point that all the evidence quoted relates to results obtained using assays that are aligned to NGSP, even though their standardisation may have been 'anchored' to IFCC.

In my humble opinion, we cannot make any decisions about the utility of HbA1c for diagnosis until all routine assays have been properly scientifically calibrated to the IFCC reference measurement system and producing results in IFCC mmol/mol units.  This requires all hardware and software elements that were introduced to align results to NGSP/DCCT to be removed and the full traceability chain to the HbA1c[IFCC] measurand established.  How many manufacturers have asserted that they have made these changes?

It should be remembered that the 1st of January this year was the deadline set by the diagnostic industry to ensure that all assays would be fully traceable to the HbA1c[IFCC] measurand and capable of producing results in mmol/mol units.  I believe that many UK laboratories are still not certain if they are producing analytical HbA1c[IFCC] results and continue to derive them by reversing the master equation.  We thus remain in a state of flux where there is a degree of uncertainty about the accuracy and comparability of HbA1c results.

Happy New Year to all

Jonathan Middle



On Mon, Jan 17, 2011 at 12:43 PM, Joseph WAWA <[log in to unmask]> wrote:
in addition to the recommendation itself***, its grading has to be equally born in mind, ie:
- Quality of evidence assessed by GRADE:  moderate
- Strength of recommendation based on GRADE criteria: conditional

***http://www.who.int/cardiovascular_diseases/report-hba1c_2011_edited.pdf

translated into the GRADE language this means that the implementation of this recommendation is "conditional" (depends on local, organizational, financial conditions, patients preferences, etc)

Dr Joseph Watine, PH, AIHP, PharmD, AAHU, EurClinChem
Laboratoire de Biologie Polyvalente
Centre Hospitalier La Chartreuse
Avenue Caylet
12200 Villefranche-de-Rouergue
France

> --- En date de : Lun 17.1.11, Paul Masters <[log in to unmask]>
> a écrit :
>
> > De: Paul Masters <[log in to unmask]>
> > Objet: Re: WHO Consultation concluded that HbA1c can
> be used as a diagnostic
> > À: [log in to unmask]
> > Date: Lundi 17 janvier 2011, 12h09
> > Irrespective of the wisdom of this
> > decision, just an observation about the units in the
> > report.
> > If even the WHO can't be bothered to use the new IFCC
> units
> > instead of %HbA1c, why should we? Is anyone going to
> > seriously turn off the old units in June?




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