I had a total thyroidectomy in 2016 and am currently pregnant, so testing my thyroid all the bloomin’ time as you can imagine.
My endocrinologist (Bupa at London Bridge) was sceptical about Medichecks after some recent strange results so for my latest check I got a blood test with Bupa (they use The Doctor’s Laboratory) in London and also got them to fill up a Medichecks vial as well which I posted that day and was confirmed received the next day. So blood taken at exactly the same time, but the Bupa test results were back the same day, whereas Medichecks took 2 business days.
My results have just come back and are worryingly different:
Medichecks:
TSH 0.226
FT3 4.14
FT4 17.2
Bupa:
TSH 0.22
FT3 3.3
FT4 15.9
Now I’m questioning all previous results I’ve had with Medichecks.
Any thoughts? Has anybody else had a similar experience?
Thanks all!!
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mushumouse
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Can you provide the reference ranges for the tests? If BUPA has a FT4 reference range of e.g. 12-19, and medichecks have a range of e.g. 14-21, then you can't compare the numbers directly like this.
Yes, that is strange! There have been a few instances of Medichecks not matching doctors results recently - with the blood samples being drawn at the exact same time! You're not the first to have an issue like this.
Hopefully one of the other's whose had this issue might be able to give some feedback on whether they got to the bottom of it...
There’s always a margin of error with every test. Expecting results to be identical is unrealistic, testing doesn’t work like that. One of the reasons test results shouldn’t be used to adjust dose.
I would ask Medichecks. They also use TDL for their blood tests although they use other labs also. When you say a via, I assume this is the test tube types that are used when a blood sample is taken. The finger prick tests might give different results because of the small amount of sample but these differences seem too much for a full blood sample.
Thanks, I will definitely email Medichecks and report back it was venous for both tests - needle stayed in my arm while the nurse filled both vials, one for Bupa one for Medichecks. The finger prick freaks me out! :-S
When the blood was collected for each test did you have one needle put into your vein and then all the vials filled from that one needle? Or did you have more than one needle put into your vein, one for each set of vials?
If the same needle was used to fill up all the vials then one would expect the results to be more similar - although I still wouldn't expect them to be identical. But if you had a needle put in one arm for BUPA and a needle put in the other arm for Medichecks then I would expect some variation to show up.
With ref ranges the same sounds like same machines. Do you know who medicheck use as TDL is used by a few. I’ve had the same happen, but sent 3 to different places. Two similar but one very off which I noticed last time bloods were sent. Conflicted now and doubting myself. Two show bad conversion, one is fine but thats the one endo sees. Xx
Email them and query it. Ask for neqas results and what platform they use for testing.
Am I missing something here? These bloods surely weren’t taken at the same time/same day/same hour? Your results are very similar for both? Sorry I don’t see the concern?
These two tests were with blood taken at exactly the same time. The nurse had the needle in my arm and filled up the Bupa vial and then immediately the Medichecks vial. The only variable is that Bupa tested the blood and got the results back to me the same day, whereas Medichecks were posted the blood so couldn’t run the test until the next day.
I’m surprised you see no concern with the numbers but I like to be very specific about it all - there is far too much variance for me and one test result has non-optimal numbers for my stage of pregnancy.
Thanks for clearing that up. I’m just being nosey - why would you need two different labs to do your bloods?
I still think they are very close, they’re not wildly different. Both FT3’s could do with improving if you don’t feel good but apart from that I really don’t see what you’re seeing. Maybe i just don’t know enough 🤷♀️
My endocrinologist was sceptical about Medichecks so I thought I would do two parallel tests to see if there was any variation. I don’t think these results will make him less sceptical! But I speak with him this week so will find out
Although I agree with you that the numbers are a bit too different, I disagree that they have different interpretations. They both show freeT3 in the bottom quarter, and freeT4 just over halfway through the range.
I would say this shows a bit of a conversion problem, in that your freeT3 is quite a bit lower than freeT4. But unfortunately it is terribly hard to get prescribed T3 these days.
Most people feel well with freeT3 high in range, and most people on Levothyroxine will need the freeT4 right at the top of the range or slightly over to feel well. I would say both results show you need a dose increase.
Blood tests are always an approximation, even if you were optimally medicated and one of these results took you a little over the range, the big question is what your symptoms tell you.
My endo has said I have a bit of a conversion issue so when not pregnant, take a mix of Armour thyroid and Levo which gets my FT3 into the 5’s and definitely makes me feel a lot better! He doesn’t like me being on Armour when pregnant though unfortunately
Going off topic slightly, re your endo not supporting NDT during pregnancy ...
it is true there are no large peer-reviewed, double-blind, journal-published studies comparing levo-only treatment to NDT, but there is significant patient based evidence supporting a substantial number who have better control of hypothyroid symptoms when treated with NDT during pregnancy ..... and generations of pregnant women who gave birth to healthy babies before the introduction of Levo.
But back on topic .... I wouldn’t be too worried about FT3 & FT4 variable results but would be looking to increase thyroid hormone amounts, given that adequate is of utmost importance during pregnancy and a thyroid hormone replacement med increase is normal as your baby doesn't use his/her own thyroid hormones until about 20 weeks old.
NICE states that TSH levels should be kept in the low-normal range (0.4–2.0 mU/L) and an FT4 concentration in the upper reference range. Your FT4 is below that. Unfortunately T3/FT3 is not usually measured.
Blood tests should be performed every four weeks during the first trimester, then 16 and 28 weeks of gestation or more frequent if needed.
The difference in TSH and FT4 isn't large and is due to inaccuracy natural in all tests. For FT3, this may be because different FT3 tests can give different results. The reason is frankly that they are badly made and badly rationalised one test versus another. They urgently need improving, but because FT3 isn't deemed an important test, there's little incentive to do it. If I was to guess which gives the more likly answer, given the TSH value, I'd plump for Medichecks.
This is very interesting but I’m disappointed to hear how the attitude towards FT3 may be impairing it’s testing - I find that’s the most important number for how I feel!
Why do you say you’d go for Medichecks, based on the TSH? Thanks!
Because with tSH of that value I would'nt expect FT3 to be as low as the BUPA value. I know it sounds odd, but two assays can have different performance even when the ranges are the same. The reason is that they are done with different populations of patients. If you crossed over each of the populations to the other test and remeasured, probably you'd now find different ranges. The identical two ranges can be just a coincidence of the populations selected to get the ranges.
Ah, I see, thank you. My Endo was also confused about my TSH being so low with my FT3 and FT4 being relatively low as well, and that’s why he hasn’t raised my dose. I was on Armour until Nov last year which saw my TSH even lower, so I don’t know if this is still a consequence of that, but it has been a while now...
I started a reply in case Diogenes didn't have time to get back to you. I suspect he trusts the Medichecks result more because in the Bupa one your freeT3 is right at the bottom of the range. You'd expect a person to feel very ill with a result like that, and therefore you'd expect the TSH to respond with a higher value.
To give you a few examples of TSH you might expect if freeT3 were as low as in the Bupa result, here are some of mine:
These were taken in order, as I increased my dose. In the third one I've got a lower freeT3 even though I was taking a higher dose. You can see here that test results can be a bit erratic! I'm also sure I felt a lot better with result number 3 even though the freeT3 has hardly changed.
You can see by the different ranges these were done by at least 2 different labs. Very interesting, I'm glad you've brought this topic up, because it might explain some of the ups and downs in my results!
Medichecks have now emailed me back, however they don’t actually answer my question which is unhelpful and doesn’t make me trust them any more.
They say:
“Different labs will have different normal ranges. Because different labs will use different analysers and test kits, measurements will not agree perfectly across laboratories. This is because each will set its reference ranges using the average results for each biomarker. If the normal ranges given by two laboratories match then you can be reasonably confident that you can compare results between them.
We use two UKAS accredited laboratories. Both laboratories use Roche analyzers if you wanted to provide the information to your endocrinologist.”
And then offered me a free retest!
They are talking about differences in ranges not actual results and the ranges are actually exactly the same!
A free retest means nothing if the results aren’t accurate and that is my concern.
I think the information about Roche analysers may be the info you need. If you go back and ask Bupa the same question you can figure out if they're both using the same system.
The retest can be useful in tracking down the issue, as at least you'll find out if both Medichecks results match. Mistakes will always happen in some percentage of cases, and with any unexpected result the first thing to think about is there may be a mix up in the lab.
you've been given a stock answer I think! A lot of complaints teams have stock paragraphs, and they just select the one they thing most closely matches your query.
I have emailed (different) customer services back in the past and said "I don't think the stock answer selected matches my query"! Although in this case, I would email back and say something like "as per my original email, the both lab reference ranges are the same, so this doesn't explain the discrepancy between the results". It's up to you if you take the free test, but also check with them whether they will cover the fee for a blood draw, as it would be unfair for you to have to pay yourself.
Thanks for your reply! It’s interesting to hear of the issues you have had with Medichecks.
I have definitely changed my dose based on their results so this does concern me, especially as I have no thyroid and obviously want everything to be optimal for my growing baby.
I always feel pretty rubbish so it’s hard to go by symptoms, which is why I like the numbers associated with blood tests.... if they are accurate! Lol
I’ve had a similar experience. Same blood draw used for GP test and vial filled and sent straight away to Monitor My Health. My FT4 was about 40% through range on one test and 60% through range on the other test. The ranges were the same. TSH results were almost the same. FT3 results not as far apart as FT4.
I think it shows we shouldn’t put all our faith in blood tests - they are not as accurate as we think.
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It definitely makes me question Medichecks - shame as they are so cheap!! 
Medichecks result - different to NHS
Hyper and hypo at the same time?! doc doesnt know what to do
Can a GP make you lower your Levothyroxine dose?
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