Measurement of dehydroepiandrosterone sulphate (DHEAS): a comparison of Isotope-Dilution Liquid Chromatography Tandem Mass Spectrometry (ID-LC-MS/MS) and seven currently available immunoassays.

•Dehydroepiandrosterone sulphate (DHEAS) is a marker of the adrenal gland.•Seven commercially available DHEAS assays were compared to ID-LC-MS/MS.•Data from our present study were compared to DHEAS data of three EQAS's.•Some of the DHEAS methods show standardization problems and/or a high imprecision.•These problems may potentially have clinically adverse consequences.