False Positive

December 12, 2011

Ok, I’m going to explain this one more time:

There is no danger of a “false positive” in testosterone testing. This discussion is specific to Ryan Braun, but it’s also the case in all modern sports testing. I thought I’d detailed this enough in my recent SI piece, but I guess it’s worth making even more clear.

The initial testing done is a simple ratio. Anything over 4:1 of testosterone to epitestosterone triggers the second, more accurate and precise test. The ratio test isn’t very accurate, which is why it is no longer used as a standalone. It used to be, until the secondary test (gas chromatography and isotope ratio) became widely available. But having a high ratio proves NOTHING; it simply triggers the more accurate test.

So why do the ratio test at all? The GC-IRMS test is expensive and time consuming. You (and the lab techs in Montreal) don’t want to do hundreds of them. The ratio test is simply a way to spend time and resources on the cases that need that kind of time and attention.

So to summarize: T/E ratio is pretty accurate, but not to be relied on. Good enough to use as a trigger. Second test? Very, very, very accurate. False positives, like masking agents, remain one of the red herrings of drug testing.

11:28am | URL: http://willcarroll.tumblr.com/post/14120262798/false-positive

(Notes: 50)