We changed the title of the thread with updated information. It was originally "Peter Bol innocent- B sample comes back negative." According to Sport Integrity Australia, his "B" sample returned an "atypical finding" which is not the same as negative and they are continuing their investigation, but his provisional suspension is lifted.
1. They'll always be a question mark about what caused the positive A and the negative B, but I guess I have to go with innocence at this point.
2. We need a Floyd Landis. The sport needs one. Right now we're in this weird murky water where we don't know if it's a handful, a few, most, or all. When he tested positive I immediately believed his guilt. We need someone to just tell us how deep doping really goes. Do people really flagrantly cheat writ large? Because if they do, it's a systemic issue not an individual runner issue.
3. I'll presume his innocence, what I will not do is give the kiss-a** media a pass for going soft on positive tests when they come out. They still need to hold athletes accountable.
I’m an MD and deal with diagnostic testing all of the time. This outcome is not surprising. Data presented on the prior main thread on this topic documented that the specificity of the A sample test alone (negative in non dopers) and therefore the positive predictive value (that a positive A sample is a predictor of true doping) is low enough for the epo assay that NOBODY should assume an athlete is a doper based on the A sample result alone.
Can someone explain why the A sample gets announced before the B sample is tested? This should all be handled quietly until the B sample comes back, and then release the information. Now some people are going to forever associate Bol with EPO, despite the false positive.
Also this false positive should be hugely concerning to any pro runner. Can someone with knowledge of the testing process tell us how common this is?
I’m an MD and deal with diagnostic testing all of the time. This outcome is not surprising. Data presented on the prior main thread on this topic documented that the specificity of the A sample test alone (negative in non dopers) and therefore the positive predictive value (that a positive A sample is a predictor of true doping) is low enough for the epo assay that NOBODY should assume an athlete is a doper based on the A sample result alone.
Part of me has always been skeptical of Lagat. Now seeing this happen to another athlete let’s me doubt them both far less
Will all those who excoriated Rinaldi now come on and apologize to him - highly unlikely. But then this is the den of those who like to jump to conclusions.
I’m an MD and deal with diagnostic testing all of the time. This outcome is not surprising. Data presented on the prior main thread on this topic documented that the specificity of the A sample test alone (negative in non dopers) and therefore the positive predictive value (that a positive A sample is a predictor of true doping) is low enough for the epo assay that NOBODY should assume an athlete is a doper based on the A sample result alone.
Part of me has always been skeptical of Lagat. Now seeing this happen to another athlete let’s me doubt them both far less
The exogenous epo assay seems particularly poorly performing. I’d have to go back to the old thread to find the study, but if I recall it was a randomized experiment where athletes were randomly assigned to receive typical doping doses of epo or not. All the athletes were then tested. There were something like 330 assays run. 14 tests came back positive as the “A” sample. 7 were positive in the dopers and 7 in the non dopers. When the assay was rerun “B”, all the 7 dopers were positive again (true positives) and none of the 7 in the non dopers were confirmed (false positives.)
Part of me has always been skeptical of Lagat. Now seeing this happen to another athlete let’s me doubt them both far less
The exogenous epo assay seems particularly poorly performing. I’d have to go back to the old thread to find the study, but if I recall it was a randomized experiment where athletes were randomly assigned to receive typical doping doses of epo or not. All the athletes were then tested. There were something like 330 assays run. 14 tests came back positive as the “A” sample. 7 were positive in the dopers and 7 in the non dopers. When the assay was rerun “B”, all the 7 dopers were positive again (true positives) and none of the 7 in the non dopers were confirmed (false positives.)
I’m an MD and deal with diagnostic testing all of the time. This outcome is not surprising. Data presented on the prior main thread on this topic documented that the specificity of the A sample test alone (negative in non dopers) and therefore the positive predictive value (that a positive A sample is a predictor of true doping) is low enough for the epo assay that NOBODY should assume an athlete is a doper based on the A sample result alone.
This is great you are here. Can you help us understand the science behind this? Was it an incorrect testing procedure at fault? In testing for certain substances are there reagents used that can create these false positives? Why is the B test a better indicator of innocence than the A (or vice versa?)
It's all super interesting stuff - if you could shed some light from your perspective that would help a lot of us - myself included, understand how this all went so wrong to begin with. Cheers.