In March Prof L Thienpont went to the USA Federal Drug Administration with the IVD manufacturers, to hear what the requirements will be for FDA clearance for FT4 test re-calibration and consistency after standardization. The requirements are:
1) -Establishment of new reference ranges
2) -Risk-Benefit assessment (to prevent patients being harmed after standardization)
3) -Education/information of clinicians.
We now have the regulatory demands clearly stated. It will take millions of £/$ to put right. Hasn't started yet, and I believe some manufacturers won't be able to comply because of cost.
FT3? The Thienpont group are developing the reference method so not there yet. It is more difficult than for FT4 so needs great care in establishing a good protocol. Watch this space.