title: Letter: Comparison between free thyroxine index and effective thyroxine ratio.
mesh_terms: D006801:Humans; D013223:Statistics as Topic; D013960:Thyroid Function Tests / Q000379:methods; D013974:Thyroxine / Q000097:blood*; D013975:Thyroxine-Binding Proteins
chemical_list: D013975:Thyroxine-Binding Proteins; D013974:Thyroxine