Hello everyone. Has this happened to anyone else? And is it likely that Blue Horizon is wrong? I paid a lot for the Gold premium thyroid test: The results of tests done at the same time as NHS ones are vastly different:
NHS Blue Horizon
Ferritin 192 ug/L 249 ug/L
TSH 1.79 m/ul 2.24 m/ul
Folate 12.8 ug/L 34.50 nmol/L*
B12 422 371
All measurements are the same format except the folate, ug/L vs nmol/L
I wanted to post here before I contact Blue Horizon. But these are so different, I wonder if anyone has come across this.
Thank you
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OllyTojo
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To be able to compare them we need to know if the ranges are the same, they rarely are. So can you add the reference ranges that come with both sets of tests please. When the ranges are different we have to work out the percentage through range to be able to compare.
Also please add the unit of measurement for the B12, I know BH's is different from my GP's. BH when I've done B12 with them is pmol/L and my GP's test is ng/L.
What about the other tests in the BH bundle, were any of them done with your GP, eg FT4?
Hello Seaside Susie. Thank you. I will put all the information tomorrow. I am brain fuddled at the moment. But those were the only tests that were done by both my GP and BH. I will add all the BH tests with ranges for both GP and BH tomorrow as soon as my brain clears. Thank you
This reply only really applies to your TSH results ..... and it has turned into a short essay , (sorry )
As far as TSH /fT4 / and fT3 tests are concerned ..... it is not a case of one lab giving an accurate result and another lab being 'wrong'.
The labs are both probably fine ... the problem is more likely the different machinery that they use to run the tests through .
Test 'platforms' made by one manufacturer do not give the exact same result as 'platforms' from a different manufacturer. (even if you put the exact same blood sample in them both, that was handled in the exact same way / travel time / temperature etc before it got there)
Some manufacturers platforms results are closer to each other than others , but some are 'more different' than you would expect .
If the NHS and the private lab have bought different platforms , they will both process the test very properly and very carefully and get 2 different results. ...because astonishingly ,nobody has yet forced the different platform manufacturers to compare their platforms and make sure they all measure the same .
Frankly, testing TSH /fT4 and fT3 is still a bit of a shambles , it has been for decades.. but it's the best we've got so far.
This is the case for all TSH /fT4 and fT3 testing currently , no matter which lab you use ....and it is because of the particular technical difficulties with using different methods for isolating and measuring those substances ... i don't think the same problem exists to anything like the same extent with 'other' blood tests , but i don't know for sure.
We commonly see loads of different ranges for fT4 tests , anything from [7.9-14] to [12 -22] to [9 -25] from different manufacturers ..... TSH and fT3 ranges from different manufacturers seem a bit more standardised than those for fT4 , but they are still not the same as each other.
and unfortunately ,while converting results that come with different ranges to a "% through range " does allow us to compare them in theory ... in practice .. in not convinced it always solves the problem totally.
See these recent posts below from diogenes (who had a role in inventing some of the testing methods used for fT4/fT3 and therefore knows what he's talking about )
my curiosity/suspicion was peaked after i got my all historic blood tests.
Since 2003 my NHS fT4 ranges (from the same lab ) have been:
[13-26]
[11.2-26]
[11-24]
[9.5-20]
[8-18]
[7.9-14] ... and when it changed from [8-18] to [7.9-14], which has a much lower top end AND is much narrower.... my '% through range' went through the roof on same dose and with same TSH.. but i can't prove it 's 'wrong' because there was one result in between where my fT4 was lower, and my fT4 has always wandered about quite a lot for no reason.
But i do find it a bit hard to believe that the latest [7.9-14] range is totally comparable to the others even when results are converted to % through range, because i used to get maybe 110 -130 % on some of the previous ranges ... but now i have had 180 -240% and last one was 140%. Mmmm. just call me 'dubious'
Good grief, they're all over the shop. Why so many switcheroos I wonder...so, over all, how reliable are the tests at all?! Especially when they are the be-all and end-all for prescribing. (I tried reading Diogenes' papers but they are way beyond my comprehension.) Can we not just take enough med until we feel better and go with that?! That's what my doc. (RIP) in the US who put me on NDT years ago did, based on my symptoms, although testing also. My bloods didn't qualify me for treatment anywhere else but with him (he was an old-school ENT consultant) so I came back to UK and had to put up with it; admittedly I'm not a severe case by any means.
Well the last change between [8-18] and [7-14] was definitely a "we bought a new machine" moment .. because the new range matches very closely to the 'factory setting' of a particular make and is so different from the previous ranges . The first three.... i assume were all the same machine with minor 'local population adjustments' being made every few years to the basic factory setting .
(this is common practice , you buy a machine set to a basic range, then you tweak that range very slightly based on real blood samples from a bunch of people from your own labs local area ... allegedly)
The other two [9-20] and [8-18] .. would clearly seem to be 'the same machine just 'tweaked' a bit lower '.... but whether this was the same machine as the first three,, or whether this lab has actually had three machines i don't know .
Can we trust them at all ?/ what's the point ?
... well certainly for anything 'borderline .. the answer has to be 'no, you can't trust any of them to be totally consistent with each other about WHERE the borderline actually is ' .
The evidence shows very clearly that 'borderline' TSH on one manufacturers machine might be 'slightly over range' on another manufacturers.
Some machines are closer than others. but it's a problem that is not fixed yet and no one making the machines is in any hurry to fix it , because nobody that buys the machines , or uses the results , is kicking up enough fuss about it .
Since i learned this, i look at blood tests done using different ranges as only being accurate enough to tell me if my fT4 is stupidly low / somewhere around the bottom of the range / somewhere middling / somewhere around the top of the range/ stupidly high.
But the next time a GP tries to tell me that i'll drop dead if i don't lower my dose because my fT4 is 22.5 [12-22] .. they will be getting the sharp end of my tongue about the accuracy of the the tools they are using to make such life changing decisions about peoples treatment.
And if i want to accurately compare my current level of TSH /fT4 /fT3 to what it was at the last test, to really know if something has actually gone up or down .. then i will have it done at the same lab , taken at the same time of day , with the same thing for breakfast, and the same gap from last dose , and the same way of getting myself to the blood test (i won't walk fast to one, and drive the next)
... other wise i don't believe it's got a cat in hells chance of being a true comparison.
It's good to use bloods as a guide alongside knowledge of signs and symptoms of over / undermedication, because even though blood tests are not perfect , IF they are used and interpreted with their limitations in mind , they give a much better picture than no blood tests at all.
The problem comes when GP's/Endo's treat them as absolutely infallible with fixed boundaries that must dictate treatment decisions with no leeway for judgement or clinical experience .
Then they are more of hindrance, causing actual harm by not allowing treatment at all , or by forcing dose changes just because the test happened to be done somewhere different.
The testing methods currently have somewhat 'blurry' borders and are certainly not all consistent with each other near those borders .. but GP's are using these tests in a tick box system that dictates extremely firm cut-off points at borders between treat /don't treat . increase dose/ don't.. which is idiotic .
I want to add one thing to tattybogle's explanation of "the problem of ranges".
As I understand it, ranges are often quoted by starting with a factory default and then making small changes to make them more compatible with the local population, as tatty mentioned. So a test machine sold to labs where the population is wealthy, healthy, and well-nourished will have different ranges to areas where the population is largely elderly, in poor health, possibly under-nourished, and probably not wealthy.
But where does the blood come from that is used as being representative of the local population? It comes from patients that doctors think are sick enough to need a blood test. So a lot of the samples come from people who are already ill. Labs also use their staff, I believe.
If a whole area suddenly gets water supplies adulterated with fluoride (as is going to happen in England - I'm not sure if the whole of the UK is going to be affected) and it increases TSH as a whole the likely result won't be that everyone will be declared to have thyroid disease - they'll just change the reference ranges to incorporate sick people in the ranges and thus declare them to be well.
I freely admit that my understanding of this subject may be very wrong - but we'll just have to see what happens to reference ranges over the coming years once fluoride is added to tap water.
There have been a lot of petitions campaigning against fluoride being forced on everyone and all of them have been rejected or closed. (I didn't look at the dates they were created - they might not be recent)
I wonder what the economic effect will be. If children have less tooth decay (something I have never researched to see what the quality of the evidence is) does it save more money for the Treasury than people developing thyroid disease, particularly since treatment is so poor, and some people end up with a very poor quality of life, and end up unable to work.
humanbean, the Australian experience provides good proof that fluoride saves teeth from decay. For example, when my staff members were in their 20s to 30s none had ever needed to go to a dentist. Their teeth were perfect. They were shocked at the experiences of the older staff.
Thanks tattybogle for all this. I suppose my problem was that my FT4 results varied from below average (GP's NHS) to very high in the range (Private NHS and Blue Horizon). Shall just show my Endocrinologist the GP's NHS results.
the benefits of this current (shonky) system of potentially different test results from different platforms is that: a) you can pick and choose which results you make GP/endo aware of, for your own benefit. and,
b) if you have firm evidence like yours of 'same blood draw/ big difference in levels '.. then the next time a GP is insisting on a dose change you don't agree with because one of your NHS results is 'too close to the limit' , you can point out to them that you are aware of this potential difference between results so they need to allow a bit of leeway .
Good point. My GP does not treat my hypothyroidism - he has admitted that he does not know much about it. I see an endocrinologist privately. My first follow up appointment is on Saturday so I will get a better insight into his approach. I am hopeful at this stage.
I think it is unlikely that GPs will accept that kind of logic about different test results from NHS and private.
When I first started to pay for private testing and tried to show my results to GPs I was told a few times that non-NHS labs were not accurate and that the companies doing them were money-grabbing cowboys. The reactions were often angry and dismissive in tone as well.
I agree they are likely to say " private tests are inaccurate" i was meaning more in terms of putting this under their nose: healthunlocked.com/thyroidu... . ie. there will be differences between TSH result from NHS labs using Roche platforms and Abbott platforms
And in all probability fT4 results from NHS labs using Beckmann -Coulter platforms with [7-14] range will differ somewhat from NHS labs using other platforms with the more usual [12-22] ish ranges
"Serum fT4 and fT3 values measured by two different kits presented moderate to good concordance but, the median fT4 levels were higher with Kit A and the median fT3 levels were higher with Kit B (p<0.001 and p<0.001, data not shown). When we compare thyroid hormones between patients and controls, thyroid hormones measured by Kit As presented more significant differences with higher AUC values for discriminating patients from controls than those measured by Kit Bs. These findings suggest that free thyroid hormone levels and their ratio might vary according to the assay methods and this way of comparison might be helpful for choosing appropriate assay kits to use."
If what you say is true, that different 'machines' give different results, then the process undermines the entire point of getting tested!!! To make a comparison, if I used a voltmeter to measure current and one device was calibrated differently than another, I'd never know the true voltage being measured!!! That's why we have 'standards' for all kinds of things, from tire pressures to fire retardants, so why don't tests for levels of hormones in the body obey the same rules?
Frankly, I'm appalled! What is the point of getting tested?
Now I know that levels change during the day and that levels change due to specific factors such as whether you've eaten or whatever, that's why specific conditions are recommended before getting tested but if the machines themselves are calibrated differently, it makes a mockery of all the things we're asked to do!
The critical difference is that all the electricians and engineers would have played merry hell by now if a tape measure from Wickes measured mm's slightly different to one from Travis Perkins, or a voltmeter from one manufacturer didn't agree with one from somewhere else.
But for some reason ( lack of giving a shit ? ) all the endocrinologists in the world don't seem to have said " oi !, this kit is all over the place, we won't use it until you sort yourselves out "
And nobody in the NHS purchasing standards dept . seems to have done anything intelligent about it either ....like ? at least make sure all the NHS labs buy the same F*** ing machine until the complex technical difficulties of testing are ironed out.
And most GP's will have no bloody idea there is even a problem at all .
I'm appalled too.
Can you imagine :
builder in manchester ~ "well, i ordered my RSJ after measuring very carefully and it doesn't fit the wall ?"
supplier ~ " Not our problem , we measured it carefully in newcastle and if it doesn't fit you must have measure it wrong "
So, clearly the medical 'profession' from the NHS to the private 'testers' don't give a shit as long as the 'test' is done. It's appalling and of course this is not confined the treating the thyroid! This is across the board! Isn't it time that something LEGAL was done about this? People pay through the nose for these 'tests' and get shafted.
You'd think so ..apparently it's been a problem with the development of thyroid blood testing for 40 yrs ...... my lack of understanding of the technicalities involved in separating/ binding /and estimating miniscule amounts of TSH /FT4 /FT3 means i can't make much of a case for it , other than have a bit of a rant about 'people using different rulers'
I can't understand the processes enough to figure out how come it's allowed to go on .... there ARE standards that have to be met for labs and test equipment .. it's not a 'free for all'
, but it would seem that perhaps they don't compare them 'to each other' often enough , or vigorously enough... and it would certainly seem that those with the purchasing power are not to fussed about applying pressure to manufacturers to solve the technical problems..... and why would the manufacturers bother if they've got a test that works consistently 'within it's own limits' and labs will buy it as it is ,
and endo's won't ask any awkward ? 's about "how come this fT4 range has just changed from [12-22] to [7-14] ... can it still be 'right' ? shall i start comparing a few of my patient's previous results to their current ones to check if it makes sense ? "
........will they 'eck as like ! .......
they'll assume it's an accurate test, and then assume the patient must not have been taking their tablets properly if the result makes no sense , because that's their answer to anything on thyroid bloods that's a bit 'unexpected'
Well, all I can is, what's the point of getting tested, except for the NHS and the testers to avoid any kind of responsibility? What a racket!!! From now on, I don't think I'll bother to get 'tested', what's the point?
well it can definitely tell you if your TSH that is usually 1.2 has suddenly dropped through the floor to 0.05 or risen close to the top of the range . It can tell you if your fT3 is utterly pant's or pretty close to the top .
it can tell you if your fT4 is more or less absent , somewhere vaguely in the normal range or stupidly high .
if you do use the same lab consistently , and use consistent test conditions /timings ( and they don't buy a new machine at an inopportune moment )....It can tell you over a few months / years that your fT4 is getting higher and higher on the same dose , or your conversion from T4 > T3 that was consistently pretty good before menopause, has become utterly crap afterwards.
Some symptoms are notoriously difficult to tell apart between a bit hyper = need to reduce dose a little, and a bit hypo=need to increase dose a little. So having a peek at what's going on in the blood can help make the decision of 'up a bit' or 'down a bit' less of a coin toss.
So it's no totally pointless.... it's just nowhere near as 'accurate' or as readily comparable between different tests as you would expect it should be, given how much weight the results carry for treatment decisions by Doctors who, nowadays, think they don't need to bother examining (or listening to) the patient thats (not) sat in front of them.
Well, I've been taking Levo for 13 years and it's never worked. In fact I 'd say that taking Levothyroxine ruined my life and I wish I'd never started on it but I didn't know any better at the time (I foolishly believed the student doctor I didn't know was a student doctor. I was diagnosed purely on the basis of a blood test. I have never, in those 13 years, ever been asked what my symptoms were by any GP (and one useless endo). At best, I don't feel as cold as I would if I lowered the dose but all my other symptoms have stayed exactly the same throughout those 13 years regardless of the dose (oh, my nails get even more brittle than they 'normally' are).
Aah. Thank you SlowDragon. Both labs flagged up that ferritin was high though. NHS would have received the sample same day and BH following day as posted next day by 1pm. So that could well explain it. Wealth of information here. Thank you
As mentioned it’s a problem… My endo told me that you could send several vials from the same sample to the same lab and they would always differ but I see yours are quite varied (apart from the folate result as I have tried on various occasions to convert so the unit of measurement matches and failed. But then I struggle with the easy stuff 🤣)
I guess that the blood samples were taken on the same day at slightly different times. The samples are therefore similar rather than identical. So there are at least three causes of variation:
The samples are different, they're not one sample split into two. I assume?
They were handled differently by different labs using different machines, protocols and perhaps even different units of measurement.
Random error. Even if the samples were identical and were sent to the same lab you can expect the results from each sample to vary. By how much? I'd guess + or - 10%.
With the exception of the folate the variance is greater than one might hope for but perhaps not completely surprising.
With blood results it is probably best to see them as broad indicators of where you and the rough direction of travel in time are rather than very precise measures. This is perhaps where the medical profession get themselves enthralled by precise looking numbers printed out by a computer rather than treating the numbers as pieces of evidence which can help build the larger picture.
Hi Cornwaller. Thank you. Both samples were taken at the same time. Phlebotomist just added BH vial at the end of the draw. The only difference was that one was sent in the post 24 hr delivery and the other sent same day to hospital. But draw done at same time. It will be very interesting to see what SeaSide Susie says about the conversions.
p.s. I am dashing to get out this morning so that was just a quick reply for now. Your input is much appreciated. I am going to read through all and assess the info more fully later. Thank you again.
Cornwaller, my samples are always from the same draw - some blood is poured into the NHS tube and some into the other Tester's tube. The differences in results still occur.
This happened to me from the very same lab (NHS) with the same blood, taken at same time and tested at the same time. I needed a blood test for endo and for GP. When I asked endo for copy of test results the nurse asked if I would like the results for both GP and endo. I said yes. I presumed they would be the same. But when the endo said I needed more meds and the GP was puzzled because he thought I needed less, I compared both results. They were completely different. One showing high and one showing low. If the numbers are different then look at the range. So if it is say 4 with range of 1 - 5 then 4 is on the higher side. If it says 9 with range of 4 - 9 again it is on the higher side. This was both the same NHS lab had the same range but one figure was low the other high.
I’d be interested to see the difference in your t4 and t3 results. Tsh is not enough to see what’s going on. I always expect a small variance between tests and best thing is always to use the same test provider to be able to see any changes.
You appear to be pursuing this - which is what I would have suggested.
Maybe, write a single email/letter addressed to both BH (or their lab) AND the NHS lab. Address to both.
Each would then be aware that you have raised the issue with the other. Which might reduce the likelihood of them blaming the other party - regardless the lack of evidence. Hopefully, when they respond, they would reply to you AND the other lab. My thought is that it gives you a way of avoiding being some sort of piggy in the middle.
If one blames the other, the other will be aware and able to respond in full.
That would be a great idea helvella but I don't have the details for the NHS lab. I just got the results by looking on my surgery records. I will email blue horizon and let them know and see what they say. I would be cautious to mention it to my GP because I'm already seen as a 'problem' patient from getting private tests done.
I'm mildly surprised that the records do not have any reference to the lab.
For many of us, the lab is obvious as it is the path lab in the nearest significant hospital. You can often find details of the lab by searching. Many labs post online something like a Pathology Handbook for users of their services. A bit more difficult in the biggest cities where distance is much less of a guide.
Ah didn't realise. I just had a look. It says pathology lab western sussex hospitals. I'll research further tomorrow. My brain goes offline after 6pm. Hope it won't annoy my GP. Thank you helvella
Below reply received from BH today. Pretty much what everyone was saying
These results are not dramatically different. It is never wise to compare levels directly between two laboratories, even samples taken at the same time. (Were they taken at exactly the same time or hours apart – even a few hours may see variations in levels of some substances?)
Each laboratory has their own controls and reference ranges, and numerically these may differ significantly. What actually matters is whether or not the tested substrates are in range or not. All laboratories have an accepted margin of error too – so for example, for a given substance, one may record a level of 10% more than is really there, and one may record a level of 10% less than is really there – both would be acceptable.
Looking at each in turn.:
Ferritin – both are on the high side. So there is consistency. Ferritin is a very reactive substance which will rise in the presence of inflammation as well as elevated iron levels.
TSH – if one laboratory is 10% lower, and one 10% higher the levels are the same.
Folate – a differential of 20%, same argument as above. Also note we are dealing with very low quantities indeed, nanomoles or micrograms, these are barely detectable amounts. Margins of error will inevitably creep up the lower the quantity of any substance present. The laboratory scientists know this and accept this is inevitable.
B12 – our laboratory recorded a level 12% lower than the NHS laboratory.
Both laboratories are actually recording broadly similar results – and no-one will be able to say which one is actually closest to the actual levels. Both are suggesting you are ‘in range’ for 3 of the 4 tested levels, and out of range for one.
Finally, your implication (I think) is that our laboratory is possibly inaccurate, and the NHS one is correct. Forgive me if I am incorrect in that assumption, but the laboratory that undertook your test for us undertakes thousands of tests daily for both the private sector and the NHS and is fully accredited by UKAS. We have no concerns with the standards upheld by this laboratory after a 10 year association with it.
Thanks for letting us know what the lab said . It would be ok if the GP's interpreted test result's with a '10% up or down ' margin of error .... but GP's don't seem to account for this 10% margin of error when it comes to TSH being low in range v below range do they.. and their guidelines don't tell them to diagnose subclinical hypo with a 10% margin of error... GP's treat TSH test results as 'exquisitely accurate', black/ white... in/ out .. have some levo / sod off .
TSH – if one laboratory is 10% lower, and one 10% higher the levels are the same.
But if one laboratory is 10% higher, and one 10% lower (that is, the other way round) the levels are even further apart! And they can't tell us which way round the labs are (in reality).
Given the results as 1.79 and 2.24:
If the first lab is 10% low and the second is 10% the results are closer:
1.97 and 2.04
But the labs could be the other way round, which would produce results which are further apart:
1.61 and 2.46
It is just an assumption that they are the way round that makes them closer.
I’ve had the same experience - split one blood draw into two vials at GP surgery - one for local NHS blood testing and the other I posted straight away to Monitor My Health (private service in NHS clinic). Despite using the same ranges I had quite different FT4 results from the two services.
Hi Bearo , the subject of wildly differing fT4 result from GP (NHS) bloods and MMH (NHS) bloods) from same blood draw, has come up again . Would you be able to share your actual fT4 results on this post ; healthunlocked.com/thyroidu... so we can compare your 'difference' to nellie's ..her MMH fT4 are consistently much higher in range than her GP fT4 .
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