Hb & OFFs: individual variance
26 Oct 2010
As we know, the UCI adopted universal values of individual variance (within subject) when it comes to the evaluation of the Biologic Passport data; that means the same values for everyone, established a priori: for Hb = 28.22, for OFFs = 71.74.
These numbers were set back in 2006 by a group of "experts in hematology and blood doping" during a WADA meeting.
25 professional cyclists voluntarily gave the results of their Biologic Passport:
As we can see on the chart above, each cyclist was subjected to an average of 19 tests, and the average values of Hb=148 and OFFs=93 are in line with those determined by the UCI and the Authors of the Biologic Passport (Haematologica 2006;91 : 356-363).
The average in individual variance for Hb resulted = 32.6, slightly superior to the universal one fixed at 28.22: all in all we can consider the 2 values to be similar.
But if we analyze the individual values of Hb-variance, we notice substantial differences, with variations comprised between 6.7 and 71.7.
Therefore, there are athletes with bigger fluctuations and others with smaller ones: if we use the universal variance = 28.22 in the calculation for the evaluation of the Biologic Passport data, those athletes with bigger oscillations (presenting a bigger individual Hb-variance) are more likely to result in "anomalies".
The observation is all the more evident for the OFF-variance: the average value among the 25 cyclists resulted = 101.0, decidedly superior to the universal value of 71.74.
Furthermore, if we try to analyze the individual values, then the differences are even more sensational: from 36.9 to 177.0!
It is obvious that the subjects presenting the biggest fluctuations are more likely to incur potential disputes with regard to a Biologic Passport adopting an universal variance fixed at 71.74.
Therefore, I am of the opinion that the individual variance of the single athlete should be used when calculating the data of the Biologic Passport, just as the "Founding Fathers" of it suggested themselves (Haematologica, 2006;91:356-363). This could reduce the possibility of "false positives" and subsequent court disputes.