We've just published an accessible article in Frontiers in Endocrinology where we discuss (in sometimes rather daunting mathematical detail) better ways of using thyroid function test measurements in diagnosis. Put simply, the best way forward is to use all the tests together (TSH,FT4, FT3) to get the most accurate answers. The ultimate aim is to produce a simple computer-generated system that puts together all the three results rather than diagnosing by looking at each one at a time. Combined with patient presentation, this destroys the notion that TSH alone is adequate as a diagnostic and gives practical methods for assessing a patient's optimum dosage. It doesn't address right away whether the programmes will suggest combination treatment as such, but I'm sure that with routine use and good analysis such forecasts would become available. The link is:
Front. Endocrinol. | doi: 10.3389/fendo.2016.00057
Calculated parameters of thyroid homeostasis: Emerging tools for differential diagnosis and clinical research.
Johannes W. Dietrich1, 2*, Gabi Landgrafe-Mende3, Evelin Wiora1, Apostolos Chatzitomaris1, Harald H. Klein1, 2, John E. Midgley4 and Rudolf Hoermann
There is also an article of ours in a similar vein in European J of Endocrinology, June 2016 but only the abstract is available from this source.
BTW I was very glad to see the scandal of gross overpricing of T3 in the UK unmasked. For your information, T3 is hardly any more difficult to make than T4, which poor excuse the sellers try to make for the high price. If so, how can T3 elsewhere be purchased so much more cheaply. I hope the powers that be think again and conduct procurement in a less amateur fashion.