But the analysis also concludes that, while the tools to obtain a far more accurate gauge of true doping levels exist, published studies on the subject are "scarce".

Interviewed by insidethegames, one of the authors, Olivier de Hon, appealed to governing bodies to take the necessary steps to compile and publish information that would permit a fuller picture to emerge.

"Our conclusion is that 14-39 per cent is the best available estimate at the moment," De Hon, scientific affairs manager at the Dopingautoriteit, the Dutch national anti-doping organisation (NADO), said.

"If governing bodies were more active and transparent in this area, we should be able to build a much better idea of the true prevalence of doping in elite sport."

It is now more than three years since David Howman, director general of the World Anti-Doping Agency (WADA), told a clean competition conference in New York that while analytical findings suggested that the prevalence of doping was about one-two per cent, "recent studies suggest double digits".

David Howman has long said that levels of doping may be higher than previous estimates ©Getty Images



Without a more accurate reading, however - and in particular an idea of whether prevalence is rising or falling - it is almost impossible to judge how effective the current policing apparatus really is, whether money is being well spent and if the inconvenience and indignity routinely visited upon competing athletes is worth the trouble.

De Hon and his colleagues, Harm Kuipers and Maarten van Bottenburg from the universities of Maastricht and Utrecht, believe that the impact on athletes imposes a degree of moral responsibility on authorities to act.

As explained by De Hon, the new analysis bases its estimate on two studies that used contrasting methods to reach their conclusions.

The first used blood readings from approximately 7,000 tests of more than 2,700 elite track and field athletes taken between 2001 and 2010, compared them with readings taken from groups of known dopers and known non-dopers, and estimated that some 14 per cent of tested athletes had an elevated haemoglobin level.

This means they were likely to have engaged in some sort of blood manipulation.

De Hon emphasised that this exercise covered blood doping only and made no attempt to gauge steroid use.

A steroid passport has now been launched by anti-doping authorities, suggesting that a similar attempt to measure steroid abuse may be possible within a few years.

The second study drawn on by De Hon and his colleagues used the so-called Randomised Response Technique (RRT) of posing questions to a group of more than 400 German Olympic-level athletes in 2007.

The principle of RRT is that you endeavour to compensate for likely reluctance to answer a direct question candidly by coupling the sensitive query with another that is harmless and whose range of responses can be mathematically deduced.

In its simplest guise, you might ask your sample to toss a coin.

You then ask individuals to respond "Yes" if their coin turned up heads or if they have resorted to doping.

In a large sample, you know that the proportion throwing heads will approximate to 50 per cent and can accordingly work out how many individuals responded "Yes" because of the doping question.

According to De Hon, in this exercise, the proportion who admitted doping was estimated at 20-39 per cent.

Russia's London 2012 3,000m steeplechase champion Yulia Zaripova is among high profile athletes to have already been implicated in 2015 ©Getty Images



While doping prevalence studies are rare, De Hon, who has worked in anti-doping for 15 years, said that others had been conducted without their results having been made public.

He appealed to those responsible to publish their findings.

He also disclosed that a RRT study is currently being conducted among Dutch national elite athletes.

He suggested it might one day also be possible to gauge athlete usage levels of certain drugs via chemical analysis of the sewage systems at training centres and the like.

A full account of the analysis -  Prevalence of doping use in elite sports: a review of numbers and methods - was published in Sports Medicine, dated January 2015.

Contact the writer of this story at [email protected]


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