Validity of immunochemical methods for bloody progesterone: a study performed in 1998]

The aim of this study was to compare, with manufacturer's agreement, twelve direct and non-isotopic commercial assays of progesterone. We have evaluated the analytical performances : low limit detection, imprecision, accuracy (recovery and dilution tests) and we have tested some patient samples. Results were compared to a reference method using isotope dilution Gas Chromatography and Mass Spectrometry combination (GC-MS). For each assay, analytical qualities and defaults are established. Large differences are found between progesterone concentration measured on the same sample with the different methods essentially for the low concentrations. Comparison with GC-MS raised questions about the accuracy of the different assays. This work will be aid laboratories to their choice and/or validation.