It is often said that FT4 and FT3 are not tested due to costs.
This seems to be confirmed by several papers which proudly claim how they have reduced costs by not doing FT4 and FT3 tests - just TSH. As well as the attitudes of medics and labs towards FT4 and FT3 testing which dismiss their importance but never actually provide any basis for claiming they positively should not be done. (Quite often, there is even some suggestion that because most of the time TSH-only is fine, that justifies almost never doing FT4 and FT3.)
I wonder what the reaction would be if a significant lab tried to negotiate with a major lab analyser to supply the tests as a bundle, TSH, FT4 and FT3?
Is there any possibility that the bundled cost wouldn't actually be any greater? At present we see so many repeated tests because FT4 and/or FT3 were not done, that itself must add to costs - phlebotomy as well as analysis. (Especially if the repeat test redoes TSH as well as adding FT4 and/or FT3.)
The analyser company might even see some advantage to supplying as a bundle. One package of reagents to be managed instead of three. Pushing themselves as a "better" supplier than the other analyser manufacturers. Increasing volume of FT4 and FT3 tests required thus reducing unit costs.
After all, we already see this approach for Full Blood Count where numerous factors are all measured without any discrimination between patients. It helps that many of the constituent tests are capable of extremely low cost implementation. But nonetheless it does suggest itself as a precedent.
Many might see advantages in other areas. No need for each and every test request to be considered and a decision made. No need for a questionable cascade/reflex approach to decide which tests. No arguments with patients. Collect a history of all three which might be of future interest even if that is not currently realised.