This morning, I had an appointment so that I could ask for a small increase in my dose of levothyroxine. Anticipating the need for some straightforward paperwork to back up my request, I thought the BTF information looked OK - simple, short, establishment-based:
The correct dose of levothyroxine is one that restores good health. In most patients this will be associated with a thyroid-stimulating hormone (TSH) reading in the lower part of the reference range and a level of thyroxine (T4) in the blood towards the upper part or even slightly above the reference range.
btf-thyroid.org/information...
I asked for an increase (from 112 to 125). Response: TSH = 2.9 - that's in range. Produced the above. Doctor wasn't happy with that statement. Reason? He doesn't know my FT4. Why? Because the nurse practitioner who did my test refused to request FT4. (The week before, the lab had been lecturing that they should only ask for TSH - it is all that is needed. Had she requested, it would most likely not have been done.)
I can't for the life of me see why not knowing FT4 apparently undermines the bit about TSH. Surely, in that sense, the lack of FT4 simply means it cannot be used to verify the second part? And if it is such an issue, well, give me an FT4 test!
The BTF paper was grudgingly accepted as being marginally better than Wiki. But dismissed as not being a proper "paper". I have booked a forklift truck to carry the printouts for my next appointment...
(I got the increase. To be tested again in two months.)