This short available paper compares the diagnoses of subclinical hypothyroidism (SCH) by two methods (Roche & Abbott). It shows that the two methods differ quite widely in their diagnosis of individuals deemed to be SCH. Confused? I certainly am, seeing the different outputs from the assays in the same person. Completely unforgivable.
Clinical concordance assessment should be an integral component of laboratory method comparison studies: A regression transference of routine clinical data approach.
First ~ the (dire) results from the previous 'sample exchange' comparison study in June 2020 .
Then ~ this regression /prediction study was done on data from June to September 2020 confirmed similar dire results .
Then ~ sometime after Sept 2020 , Abbott and Roche made an 'improved TSH assay agreement' with each other .
and now ~ we don't actually know how much closer together they are since they 'improved' things ?
How the NHS have the brass neck to go banging on about 'we must use evidence based medicine/ guidelines ' in the light of this sort of finding is beyond me.
Surely somebody in the NHS is supposed to make sure all the test platforms measure the same BEFORE they buy different platforms for all their labs ?
Yes, i know , i know ....'it's complicated '..... but really! ....It's like getting done for speeding on the M6 in Cumbria (when you were only doing 69mph in Lancashire) just because Cumbria Police bought their speed camera's from Roche, and Lancashire buy theirs from Abbott.
Well i hope at least somebody is looking into whether results have actually got any closer between Roche and Abbott machines since the new agreement was made .
I still want to see proof of how the fT4 platform (Beckmann -Coulter?) using [7.9 -14] ish ranges compares to the platforms using the higher [12-22 ]ish ranges.
I wish somebody would do a current comparison of them.... This old paper from 2012 expresses serious doubts about the use of the [7.9 -14 ] ish range. saying the top end is considered too low , it looks like they had to 'increase' it to 16 to get their study to work out ... ( it's a bit over my head ) ...
p.s ..... only vaguely related to the subject of diogenes post , but i just found the following paper detailing which manufacturers platforms are affected by biotin and 'in which direction'.
Endocrine Reviews, Volume 39, Issue 5, October 2018,
" ..... It is essential to note that the impact of biotin is directly related to the type of platform used (54, 58, 59). In Roche platforms, TSH, FT4, and FT3 may be affected by excess biotin. In Ortho Clinical Diagnostics platforms (Raritan, NJ), only TSH can be decreased because FT4 and FT3 do not use the biotin-streptavidin interaction. The opposite is true on Beckman Coulter Diagnostics platforms (Brea, CA), in which FT4 and FT3 can be elevated, whereas TSH is not affected (53, 54, 60). Interestingly, the Centaur FT4 platform (Siemens Healthcare, Erlangen, Germany) uses a preformed streptavidin-biotin complex not sensitive to the presence of biotin (53). Abbott and DiaSorin (Saluggia, Italy) immunoassays are also not affected by biotin, because the biotin-streptavidin immobilization system is not used for TSH, FT4, and FT3 measurements. Therefore, one of these last three platforms may represent the method of choice for indirectly identifying biotin interference.
The biochemical results obtained in patients taking biotin may erroneously affect the evaluation of thyroid status in different ways on different platforms. Hence, endogenous or exogenous hyperthyroidism may be suspected when hormones are measured on the Roche and Siemens platforms, subclinical hyperthyroidism or any other cause of isolated TSH diminution may be mistakenly diagnosed on the Ortho platform, and resistance to TH or drug interference (e.g., amiodarone, heparin) may be evoked on the Beckman Coulter platform (8–22). It is crucial to bear in mind that the clinical presentation of hyperthyroidism may overlap with several features of neurometabolic disorders, conditions that are treated with high biotin doses (61). Furthermore, the setting can be even worse, because anti-TSH receptor antibodies may wrongly show up as positive due to the biotin presence (49, 54, 56, 58, 62–64) ...."
I think we need a way of posting this sort of information - a bit like Wikipedia - where the current and historic comparisons are available. Having to go off and ferret around PubMed makes it much harder than it should be.
I get cynical sometimes, and the frequency is increasing. Medics are customers. In another light, what would a situation based on ordinary day things be tolerated if one seller's scales said 1 kg and another 0.8kg and yet another 1.2 kg. A hard hand would come down and rationalisation of results demanded. For me, medics are at the gullible end of the spectrum. Almost anything goes, regulation is pitifully inadequate, and manufacturers drag their feet on re-design because it will cost for no financial benefit. You cannot do useful things with compromised materials.
I've been banging on about the way that medics seem welded ( yes, welded!) to TSH labs with detrimental consequences for patients.Yet the patient is expected to meekly accept the spiel given by the doctor as to why they cannot possibly be hypothyroid ...when Frees ( however un/reliable) and signs and symptoms indicate the opposite.
If the assays are not accurate and consistent then the suffering patient is up a creek without a paddle!
And the medics involved cannot understand why!
But, your lab result indicates....
As the patient sits there feeling miserable and lost.
They are taught to treat by numbers not by knowledge based professional judgement.
If they were, surely their ability to clinically evaluate the patient would tell them these assay "numbers" can be misleading ...and prompt further investigation.
But no!
They are bound by their "masters" to follow the numbers.
Yet they overlook the science!
Increasingly we see examples of patients falling victim to this nonsense.
And lack of consistency.
There are brilliant medics but they are too often being led by incompetent, money wasting, bean crunching management who know little about the "institutions" they are tasked with managing.
It's happening in universities too, money rules.....so what can we expect from our next generation of ( medical) students.
Will they get the education they deserve and we the medics we need!
What will they use to diagnose their ( thyroid) patients who are all different, with different needs.
Well educated hands-on humans or remote unreliable machines?
The older I get the more cynical I become....and the more I rant.
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