Evaluation of the Technicon Immuno 1 free thyroxine assay.
The Technicon Immuno 1 free thyroxine (fT4) assay, a modified two-step procedure that is fully automated on a random access analyzer, was evaluated-at two clinical sites. The method had excellent precision and correlated well overall with three other estimates of free thyroxine: free thyroxine index (FTI) measured on the Immuno 1; the Abbott IMx fT4 assay (Abbott Park, IL); and the Clinical Assays two-step manual fT4 assay. Using a combination of thyrotropin and FTI assay results as a "gold standard" for defining thyroid status, the Immuno 1 fT4 method had a sensitivity of 100% and specificity of 98.3% for hyperthyroidism, versus 93.8% and 99.3%, respectively, for hypothyroidism. In conclusion, the Immuno 1 fT4 assay is useful in screening for thyroid disease.
Bock
J L
JL
Department of Pathology, State University of New York at Stony Brook 11794-7300, USA.
Morris
D
D
Cheng
J
J
Ehresman
D
D
D001322:Autoanalysis; D005069:Evaluation Studies as Topic; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D012016:Reference Values; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000032:analysis; D013974:Thyroxine / Q000097:blood*
D012709:Serum Albumin; D013974:Thyroxine