I thought I would forward this observation from one of my German colleagues on the quality of the RCP recommendations on thyroid treatment. Says a lot.
This is rather disappointing. Their recommendation is reductionistic and over-simplifying. Although it is correct that the majority of hypothyroid patients is well treated with L-T4 alone, the guideline has a general and very strong tendency against substitution with L-T3 or a combination of T4 and T3 even in a minority of patients. Interestingly (and consistently with their tendency) they only give dosage recommendations for switching from L-T3 to L-T4, not vice-versa.
Obviously, they completely ignore the 10% of hypothyroid patients who have poor QoL despite normal TSH levels. Given the prevalence of hypothyroidism this amounts to 0.5% of the total population. Therefore, "syndrome T" (inability to use T4 only) isn't a rare disorder.
Their main interest seems to be low costs of medical care. However, even in this respect they are wrong, since inadequate treatment modality may have significant consequential costs, up to premature pension of affected patients.
Interesting is their statement "Patients with suspected primary hypothyroidism should only be diagnosed with blood tests including measurement of serum TSH". Obviously, the clinical presentation of the patient is dispensable for them, and they only regard TSH concentration as essential. This isn't good medicine.