The World Anti-Doping Agency (WADA) has decided to strip so-called "aggregated data" out of its annual testing figures report, reducing the number of samples included by more than 20 per cent, based on 2018 figures.
The Montreal-based agency said that the move reflected the "increased focus on signatory results for WADA, the (World Anti-Doping) Code and international standards."
It indicated that the excluded data is not reported into the Anti-Doping Administration and Management System (ADAMS) and is "predominantly from professional leagues and universities in North America."
The newly-published 2019 report is said to show a 5.5 per cent increase, from 263,519 to 278,047, in the number of samples analyzed and reported into ADAMS.
There was said to be a decrease in the proportion of Adverse Analytical Findings (AAFs), or positive tests, from 1.05 per cent in 2018, when AAFs totaled 2,774, to 0.97 per cent in 2019, when there were 2,702 AAFs.
In the original 2018 report, including the "aggregated data", the number of samples analyzed was put at 344,177 and the number of AAFs, or positive tests, at 4,896.
If the recalibrated 2018 figures are deducted from those originally reported, the implication is that 80,658 (ie 344,177 minus 263,519) samples from the now excluded aggregated data were analyzed.
That amounts to 23.4 per cent of samples included in the original 2018 report.
These 80,658 samples would, moreover, appear to have included 2,122 (ie 4,896 minus 2,774) AAFs, or positive tests.
That is equivalent to a proportion of 2.63 per cent – far higher than that reported for the overall data-set.
If these now excluded samples do indeed relate "predominantly" to "professional leagues and universities in North America", the implication – though it can be no more than an implication – would seem to be that their positive test rate is significantly higher than the overall average, which was 1.42 per cent.
No Summer Olympic sport had a positive test rate of more than 1.8 per cent in 2019, with only six such sports – boxing, cycling, equestrianism, rugby union, weightlifting and wrestling - recording rates of one per cent or above.
In the original 2018 report, with aggregated data still included, 10 Summer Olympic sports had positive test rates of one per cent or more.