Athlete Haematological Passport
The figure has been obtained from the Athlete Biological Passport software. It represents the longitudinal profile of the markers haemoglobin, OFF-score, ABPS and reticulocytes for a Caucasian male endurance athlete. The blue lines represent the results of the tests. This athlete has been tested 9 times. The red lines present the personal limits on the expected values of the markers given the information available on the passport for a specificity of 99%. For example, for haemoglobin, the initial upper limit before the application of a first test is 172 g/L, the lower limit 124 g/L. The limits become progressively individual in the course of acquisition of successive test results. From a statistical perspective, this individualization corresponds to the nullification of the between-subject variance of the marker. If a new 10th test is carried out for this athlete, the individual limits that will apply are 127 g/L and 156 g/L. If the result of this test is out of this range, a closer examination will be performed by a panel of haematologists to see if this large deviation has a pathological origin or is due to doping. Both a medical condition or doping are good reasons to declare the athlete unfit and to withdraw him from competing for a short period. In this example, the upper limit at 156 g/L is significantly lower than the limit that was fixed at 170 g/L by several sport organisations in the 1990's to put a brake on rEPO doping, but this value at 156 g/L ensures nevertheless a higher specificity, because we have used the athlete as his own reference.
The colour bars below the graphs represent at which percentile the whole sequence of 9 values – rather than one single value – is in the probability distribution of sequences expected from controlled, clean athletes when the testing protocols specific to the passport have been followed. A high percentile is suspicious of an abnormality and will deserve closer scrutiny. A high value can be reached even in the conditions when no individual value has broken a single limit, typically when the athlete is monitoring his blood profile via low doses of rEPO and/or IGF-1 and hemodilution. This second approach based on the evaluation of a whole sequence is known to provide a much better sensitivity to any blood manipulation – if coupled with a well-thought test distribution plan – than the comparison of a single value with its corresponding limits.