title: Data-reduction methods for immunoradiometric assays of thyrotropin compared.
abstract: In an attempt to optimize curve fitting for immunoradiometric assays, we investigated eight data-reduction methods with two commercially available assays of thyrotropin. In four of these methods linear data-reduction models are used: logit-log programs of Iso-Data, Micromedic, and Hewlitt-Packard, and probit-log of Hewlitt-Packard. The other four were nonlinear data-reduction models: Iso-Data's "French curve" (modified spline), four-parameter logistic function, and point-to-point methods, as well as a nonlinear least squares method. In using the eight data-reduction methods on data from analyses of 78 patients' samples, we found clinically relevant differences between models. In fact, differences found by changing data-reduction models were greater than the difference between the two commercial kits.
mesh_terms: D006801:Humans; D006980:Hyperthyroidism / Q000097:blood; D007037:Hypothyroidism / Q000097:blood; D007118:Immunoassay; D007457:Iodine Radioisotopes; D008433:Mathematics; D011933:Reagent Kits, Diagnostic; D012984:Software; D013223:Statistics as Topic; D013972:Thyrotropin / Q000097:blood*
chemical_list: D007457:Iodine Radioisotopes; D011933:Reagent Kits, Diagnostic; D013972:Thyrotropin