Thanks for your feedback!
I'm not at home, so I've not all the sources with me, and I should ask the dev. I remember that some studies addressing multiple cohorts were applying these types of calibration.
Below are two articles I found back that raise the fact that some immunoassays are biased compared to LC-MSMS measures.
According to the two articles below, some of them come with a linear deviation on the normal male range. It usually has a minor impact (~10%).
// T measurements
Measurement of Total Serum Testosterone in Adult Men: Comparison of Current Laboratory Methods Versus Liquid Chromatography-Tandem Mass Spectrometry (jcem0534.pdf)
// SHBG measurement
https://journals.sagepub.com/doi/pdf/10.1177/0004563219888549 (0004563219888549.pdf)
Voilà!
Thanks for your question!
