title: External quality control for T3 and T4 assays in Italy: outline of the scheme and results of the first semester experience.
mesh_terms: D003951:Diagnostic Errors; D006801:Humans; D007373:Interinstitutional Relations; D007558:Italy; D011786:Quality Control; D011863:Radioimmunoassay / Q000592:standards*; D013974:Thyroxine / Q000032:analysis*; D013997:Time Factors; D014284:Triiodothyronine / Q000032:analysis*
chemical_list: D014284:Triiodothyronine; D013974:Thyroxine