Who will win the drugs race?
Box 1 | Statistical profiling – setting better benchmarks?
Setting the benchmarks above which an athlete is deemed to be a drug cheat is a difficult issue for sporting bodies. Athletes may experience mental and physical stresses that may affect their natural production of hormones to a point where non-users return ‘positive’ test results. Others have naturally high levels of production – for example, Finnish cross-country skiing champion Eero Mäntyranta, who won two gold medals in the 1964 Winter Olympics, had a genetic mutation which enabled him to produce unusually high levels of erythropoietin (EPO). How can we set fair benchmarks that catch the cheats but don’t return ‘false positives’ on athletes operating by the rules?
One possible solution is called ‘statistical profiling’. This involves gathering data on the levels of different substances in the body, during and after exercise. It would mean obtaining samples from a large number of athletes but it would also need ‘longitudinal’ data, which involve samples from the same athletes over time. With large quantities of such data, it should be possible to construct a population profile of natural levels of various substances in the body and how they vary under different exercise and dietary regimes. Such a profile would have a distribution that can be represented in a graph – a normal distribution, for example, can be represented as a bell-shaped curve, with most values occurring around the centre of the distribution, tapering off towards the upper and lower ends. From this, a probability can be attached to particular levels of substances in the body, which would help in setting reasonable benchmarks above which an individual would almost certainly be a drug cheat.
Australian scientists have been developing ‘blood profiles’ for the detection of EPO use. This involves administering either EPO or a placebo to volunteer athletes and then tracking changes in the blood over time. Those athletes administered with EPO may be expected to show increased numbers of red blood cells, including a higher number of new or maturing red blood cells. The study, which initially involved 27 Canberra-based volunteers, is now being extended worldwide so that an international statistical profile can be developed.
Page updated March 2006.