Highly sensitive assays of serum-thyrotropin in the diagnosis of XXXX : assessment of performance and reference values.

@entity1 @entity1378 @entity3214 @entity1374
The performance of three different highly sensitive immuno-assays for thyrotropin in serum (S-TSH) was compared. Specimens from 803 @entity1 with suspected hyperthroidism or other @entity1374 were used. @entity1378 @entity1 were identified and characterized by determining serum thyroid hormones and by clinical observation. The performance of the methods in discriminating between @entity1378 and @entity3214 was described in terms of diagnostic sensitivity and specificity. The performance was also assessed by systematically varying the reference values. If @entity1 with treated hyperthroidism were eliminated, the three S-TSH assays performed equally well at a suggested lower reference value of 0.4 mU/l. A diagnostic efficiency of more than 0.95 was achieved at the observed prevalence of disease (0.12). A graphical model which allows an adjustment of reference values to favour sensitivity or specificity is presented. Reference values were also calculated from the euthyroid subjects using parametric and non-parametric approaches. The specificity, when using the recommended discrimination level, suggests that @entity1 with low S-TSH values should be subjected to further investigation by biochemical or other methods.
