Detecting a banned foreign substance in a blood or urine sample should be clear evidence that a sports person is guilty of cheating chemically. But even when athletes test positive, what are the chances that they are actually guilty of doping? There are so many legitimate medications that can give false positives and so many natural chemicals in the body that unraveling the testosterone from the testy analysis is difficult.
In a commentary in Nature published today, statistician Donald Berry of the MD Anderson Cancer Center, at the University of Texas, in Houston, reviews the evidence released from the case of deposed Tour de France champion Floyd Landis and says that flaws both in the practice of drug testing and the logic by which it is applied make it impossible to conclude one way or the other whether a particular athlete was guilty of doping.
Sports careers, medals and reputations really do depend not just on performance, but also on the results of drug tests, it is crucial that testing improves.
Berry argues that procedures need to become more scientific. Sports-doping laboratories must “define and publicize a standard testing procedure, including unambiguous criteria”, he says.
Additionally, the substance used, the dose, the method of delivery and individual metabolisms all need to be taken into account when testing is undertaken to avoid false positives and false negatives and to ensure that doping at the Olympic Games and other events are as rigorous and reliable as is possible.