Study to demonstrate the potential of the use of indirect markers as sufficient evidence of different types of doping.

The objective of this study was to show that it is possible to use indirect markers as sufficient evidence of different types of doping, including blood doping, steroid and hormonal abuse. The biological passport contains all the necessary information useful to make better decisions on the basis on indirect markers, such as the athlete’s physiological characteristics and results of past blood and urine tests making it possible to use the athlete as his or her own reference.

The results of blood and urine tests were obtained by pooling data from clinical studies and anti-doping tests in order to study the variations in indirect markers that have natural, analytical or artificial causes. Only Bayesian methodology allows one to abandon the notion of causality (doping=effect <-> marker=cause) and to determine whether the observed variations are natural or result from doping.

In this work, we integrated into a Bayesian network different components of variance of blood doping markers and steroid doping makers. The created network also included models of heterogeneous factors such as the influence of altitude on blood markers. The Bayesian network has been validated and applied to more than 20,000 blood or steroid profiles. Currently, Athlete’s Biological Passport is used by WADA.