Over at DPF, folks have been poking around the per-lab AAF statistics, no doubt provoked by the 300% higher rate claimed for LNDD in the Landis opening statement. We first looked at lab stats back in September, using the 2005 data. These are new observations using the 2006 data.
First, Nomad takes a look:
I finally went back to look at the data more closely. Incidentally, a direct link is:
The distribution looks vaguely gamma, but the fit wasn't all that great. Anyway, some interesting things:
The mean percent AAFs was 2.16, while the percent total AAFs was 1.96. That's probably mainly because UCLA, which does 3x as many tests as anybody else, has an AAF rate of .99. However, in general the larger labs seem to have fairly mainstream results, with Paris and Ghent, Belgium being exceptions.
The variance of the AAF rates is 2.14, standard error is 1.47. So talking about being 1/2 the average rate doesn't really mean the same as being 2x the average rate. Being as low as .48 is still within 1, while LNDD, at 5.41 is 2.3 or so over. Of course, this distribution isn't normal, having no left tail, so we can't really talk in terms of confidence intervals directly. Somebody with more stats knowledge than me can probably tell us more on this, but it's pretty academic.
Cycling has an A sample AAF rate of 4.17%, over a full percent higher than any Olympic sport. Some of those are TUEs, and some are multiples on the same athlete as in the case of a longitudinal T/E study. But the same can be said of other sports, so the higher rate is definitely a bad thing.
LNDD finds 12% of the total AAFs in the system, more than any other lab. They only do 4% of the total tests. In contrast, the next highest lab in terms of % total AAFs is UCLA at 9.4% of AAFs, but it does 20% of the tests. (OK, that should've been easy math from their AAF rate being half as much the average.)
LNDD finds 10% of all testosterone AAFs, which is more than one would expect from their share of all tests. Their 12% rate seems to be at least somewhat a consequence of a lot of cannabis use, (nearly 20% of the total) though UCLA and Montreal have a lot of those, too.
Under the category of strange statistics.
Paris reports 2.38% of all the tests that it runs as positive for anabolics.
UCLA reports 0.37% of all the tests that it runs as positive for anabolics.