Thyroid UK

Monitoring thyroid function in patients on levothyroxine: audit findings and suggested change in practice

Today I fell across a brief letter suggesting that the intervals of Thyroid Function Tests are currently inappropriate. Typically, those with test results that are in range get tested more frequently than those who are out of range.

They might have a point.

The problem is their solution. That the lab should issue the requests.

We already have the situation in which labs refuse tests - and don't properly report back to the requester.

There are so many ethical issues. Who is responsible if a patient doesn't get the test they should? At least our relationship is currently (at least theoretically) with our doctors. Adding another party is concerning. Especially as it would very likely be implemented as a computer function without any personal responsibility being obvious.

If our FT3 doesn't get tested today, it is our doctors who we can blame, even if they shrug their shoulders and blame the lab.

Int J Clin Pract. 2017 Jan;71(1). doi: 10.1111/ijcp.12877.

Monitoring thyroid function in patients on levothyroxine: audit findings and suggested change in practice.

Scargill JJ1, Livingston M2, Holland D3, Khan A4, Duff CJ5,6, Fryer AA5,6, Heald AH4,7.

Author information

1Department of Clinical Biochemistry, Salford Royal Hospital, Salford, UK.

2Department of Blood Sciences, Walsall Manor Hospital, Walsall, UK.

3Keele University Benchmarking Service, School of Pharmacy, Keele University, Staffordshire, UK.

4Department of Medicine, Leighton Hospital, Crewe, UK.

5Department of Clinical Biochemistry, University Hospitals of North Midlands, Stoke-on-Trent, UK.

6Institute of Science & Technology in Medicine, Keele University, Staffordshire, UK.

7The School of Medicine and Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK.

PMID: 28097763

DOI: 10.1111/ijcp.12877

No abstract currently visible on PubMed.

We propose that direct requesting from the clinical labora

-tory (with a facility for clinician over-ride) may bring patients more

quickly to target with their TSH levels and reduce costs in relation

to unnecessary testing of TFTs when patients are already biochemi

-cally euthyroid. Such a change in practice, while requiring thorough

evaluation, has the potential to save money and improve patient outcomes.

14 Replies

Hi helvella,

I understand your issues with the implications of any change and am not arguing with that. But I do have experience of an area - different condition obviously - where something similar does work. I was on warfarin for a while, which needs constant (up to 3 times/week) monitoring until therapeutic levels and then regularly thereafter. This process was actually controlled by the pharmacy at the nearby hospital, with blood being taken at GPs by nurse, but follow-up, dose adjustments and communication then being done by the pharmacist. It worked well. How many patients are involved in this as compared to thyroid I don't know. Would it work for thyroid - don't know. But I thought there was enough of a parallel to mention it.



Thank you, startagaingirl, for that very relevant contribution.

Where there is a clear and readily measured end-point, I can see a process such as you describe working if everyone does their bit. Is that the case with warfarin?

With thyroid, we have the never-ending issue of reference ranges designed for super-tankers to pass. Simply having TSH within range (we all know that would be the biocehemical definition of "euthryoid") isn't sufficient.

If we (patients) don't feel right, we just might be more likely to raise it with a doctor than a pharmacist or lab letter. We could end up not seeing anyone (other than the phlebotomist) for many years.

Also, how does the contact process work? How does the pharmacist or lab contact us a year after we moved house? Not insuperable, but needs proper evaluation and implementation.


Typically, those with test results that are in range get tested more frequently than those who are ouyt of range.

Really? What sort of logic leads to this situation? How can this possibly happen? Or is it a typo?

*Brain explodes*


Perhaps the writer types in received pronunciation?


Helvella's sentence was :

Typically, those with test results that are in range get tested more frequently than those who are out of range.

I thought helvella's sentence should have been :

Typically, those with test results that are out of range get tested more frequently than those who are in range.

If his original statement was correct then I simply can't understand how that situation could ever have arisen. It would involve someone consciously saying to themselves :

"Ah yes, patient X... Thyroid hormones out of range last year, no need to test this year."

And that doesn't make sense in this or any other universe.


The response from endos & GPs doesn't always, either!

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My apologies. The original sentence is below. It makes it clear that the frequency is relative to falling in or out of range.

Relative to recommended monitoring intervals, testing frequency

tended to be too short for those with normal initial TFTs and too long

for those with TSH and/or fT4 outside the reference range.

I should have made that clear - also corrected my typo.


It's probably right as those with TSH near top of range keep going back for more tests in order to get to the magic 10, and those on levo who feel bad but have "in range" TSH also request more tests in order to get an increase, while those who are overtly hypo or hyper by NHS standards get tested once when out of range and put on meds/given TT. Then they fall into the first category with in range TSH but are being monitored every 6 weeks etc if they are lucky. Or somethign like that.


I know that two heads thing lol. A friend had a tt few years back. She had her levo decreased to bring her tsh up. She put on weight is sluggish and tired plus foggy brain. Gp and endo say shes all fine as tsh is where they want it and she just accept5s this. I did try to help and got the "who are you to question a gp/endo" look. Oh well at least i tried to help...


You can only help those who want to be helped.


pharmacist ( or the company employing pharmacist) motivated by government payments


Helvella, I found this on Researchgate. Does this help clarify?

Introduction With demand for endocrine tests steadily increasing year-on-year, we examined thyroid function test (TFT) frequencies in patients on levothyroxine replacement therapy to assess the effect of initial TFT results and request source on TFT re-testing interval. Methods All TFTs performed by the Clinical Biochemistry Departments at the Salford Royal Hospital (2009– 2012; 288,263 requests from 139,793 patients) and University Hospital of North Midlands (2011-2014; 579,156 requests from 193,035 patients) were extracted from the laboratory computer systems. Of these, 54,894 tests were on 13,297 patients confirmed to be on levothyroxine therapy in the test cohort (Salford) and 67,298 requests on 11,971 patients in the confirmatory cohort (North Midlands). Results In the test cohort, median TFT re-testing interval in the total group was 19.1 weeks (IQR 9.1–37.7 weeks), with clearly defined peaks in TFT re-testing evident at 6 and 12 months and a prominent broad peak at 1–3 months. Median re-test interval was much lower than recommended (52 weeks) for those with normal TFTs at 31.3 weeks (30.6 weeks for the confirmatory cohort). Where thyroid-stimulating hormone (TSH) was elevated and free thyroxine (fT4) was below the reference range, re-test interval was much longer than is recommended (8 weeks) at 13.4–17.6 weeks (7.1-23.4 weeks in the confirmatory cohort), as was the interval when TSH was below and fT4 was above the normal range, at 16.7–25.6 weeks (27.5-31.9 weeks in the confirmatory cohort).

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That sounds even worse than now. Concentrating on TSH and wanting not to test FT4 and FT3 even when requested

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Hello helvella,,,I only get TFT tested when I ask for it,,and the 'range' seems to be a set of figures that do not help understanding how the condition is being controlled,,,and the confusion that already exists, is going to get worse,,,nobody explaining anything to anybody,, the patient is going to feel in the wilderness,,,as an u/a thyroid patient,,I sometimes wonder what is right for me,,,and are the meds really helping me,,well I also noticed that my local hospital,, Leighton Hospital in Crewe is mentioned in the report,,,so what do I draw from that,,,maybe I should get to see and endo to find out were I am at with my levo meds,,,and will a computer really be better to monitor things,,,as they are only programmed by 'humans', so ttfn from karen.

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