[RC] Drug testing - detection and sample size - Truman Prevatt
While this debate is raging it might be of interest to take a look at
some numbers to see just how big a sample you need in order for drug
testing to be effective.
Of course the best way to approch it is to test every starter. But with
20,000 starters and say 50 bucks a test that a mllion bucks which is
quite impractical - so random testing is the only option. But if the
probability of a starter being on drugs and that drug being detected by
the test then if you don't test enough then you won't detect any drug
use.
For example assume that one in 2000 horses that stars (or .05%) does
so on durgs. Then unless you test at least 1386 horses you will have a
50% probability of not detecting any drug use. Another words to have a
50% chance of getting at least one positive drug test you need to
test at least 1386 horses if 1 horse in 2000 starts is on drugs. To
have a 75% chance of detection you need to test at least 2772 and for a
90% chance of detection you need to test 4605. That is to assure a 50%,
75% or 90% detection for one horse in 2000 starting on durgs you would
need to test 6.8%, 13.9% or 23% of the starters. Again assuming 50
bucks a test the cost becomes $69,300, $138,600, $230,205.
For a higher durg use probability say 1 in 500 the numbers for 50%, 75%
and 90% chance the minimum number of horses tested becomes 347, 693 and
1151. For this level of drug use you would need to test 1.9%, 3.5% or
5.8% for the starters for a cost of $18,700, $34,650 or 57,500.
So the question boils down to what is the underlying probability of
drug use and are we testing a sufficient number of horses - that is are
we putting enough resources toward the problem. I don't pretend to know
the underlying probability of a starter being on a detectable drug in
sufficient concentration to test. But I would expect it is closer the
the 1 in 2000 than it is the one in 500 - or else we have a serious
problem. At those low levels it is an expensive proposition to test
with any certainity that you do detect any drugs at all.
>From my experience we do not test anywhere close to one percent of the
starters much less 5 or 6. So the question is - all the philosophical
differences aside - are we even close to testing a sufficient number of
horses to make the drug testing an effective tool? Yes we might catch
one every once in a while - but how effective is it really in deterring
the use of drugs. Also looking at these numbers one has to wonder if
the drug testing program is not grossly underfunded.
I did notice that the FEI tested 2000 horses total in all diciplines.
It would be interesting to know how many horses participated in FEI
events or what percentage of the horses they did test. Then it would be
of interest to know how many FEI endurance starters there were compared
to their testing rates.
It would also be of great interest to know exactly how many endurance
horses the AERC and state of CA tested. My gut feel it's closer to the
300 level - if that and the question is that sufficient?
Truman
-- We imitate our masters only because we are not yet masters
ourselves,
and only
We
imitate our masters
only because we are not yet masters ourselves, and only
because
in doing so we
learn the truth about what cannot be imitated.