Measuring salivary testosterone with enzyme-linked immunoassays (ELISAs) is of critical interest to social neuroendocrinologists studying testosterone’s role putative in aggression, risk-taking, relationships, and dominance, among others. However, testosterone concentration measurements between various ELISAs differ considerably, and little is known about how accurately different ELISAs assess testosterone. In this research, we compare 100 testosterone concentrations from a mixed-sex sample between the ELISAs of three commonly used manufacturers (DRG International, Salimetrics, and IBL) to a highly accurate reference method, liquid chromatography tandem mass spectrometry (LC-MS/MS). Using nonlinear nonlinear, heteroscedasticity-corrected regressions and structural equation modeling, we found that compared to ELISAs from Salimetrics and IBL, ELISAs manufactured by DRG International provided the closest approximation to LC-MS/MS testosterone concentrations with the least measurement error. Additionally, the correspondence between DRG and Salimetrics was nonlinear, with correspondence flattening in the highest of testosterone concentrations, potentially due to increased measurement error. Our results also suggest differences in the accuracy of different ELISAs for assessing testosterone in males and females, with DRG ELISAs providing the most accurate assessment for both men and women. Broadly, the popular testosterone ELISAs were not as accurate compared to consistencies between cortisol ELISAs and LC-MS/MS in previous research. Overall, this work provides researchers with information to better measure testosterone in their research and compare testosterone measurements from different ELISAs. We close recommending critical next steps to improve testosterone assessment in social neuroendocrinology research.
This research has now been published in the following paper:
Welker, K. M., Lassetter, B., Brandes, C., Prasad, S., Koop, D., Mehta, P. H. (2016). A comparison of salivary testosterone measurement using immunoassays and tandem mass spectrometry. Psychoneuroendocrinology, 71, 180-188. doi: 10.1016/j.psyneuen.2016.05.022