Lies, Damned Lies and (DEFRA) Statistics
email received Jun 24 2004
Defra have released figures showing a (supposed) 14% drop in Tb
during the
last 4 months Jan - April 2004. But all is not as it
seems. "2001 was an
'extraordinary year' " due to FMD
and very little testing took place, so Defra advise "do not use as a
comparison". 2002 was catch up and carried a similar warning.
" Not to be used for comparative purposes" But also in the small print
is a note that "Defra hope to eliminate the BACKLOG of overdue Tb tests
(due to FMD) in April/May 2003"
SVS confirm that they weren't up to date
with testing until autumn 2003 at
least in Cornwall. So the last 27
months at least, Defra advise not to use
for comparative purposes.
And then they have done just that!! Comparing 2003 with 2004 and
arriving at -14% drop.
Neither have they tested the equivalent number of herds in that
period, nor cattle. 2000 less herds, and 100,000 less cattle.
If January - April 2004 is compared with the last year which had
no atypical or
extraordinary events, which carry Defra health warnings, then
January - April
2000 is the next valid reference year with
which to compare.
Number of cattle slaughtered in the same period that year (2000)
= 3,100
Number of cattle slaughtered in 2004 = 7,701.
Increase = 149% ....
...Can't get the number of herds or new incidents from Defra. They
say it is 'confidential' and referred me to the press office!
I'd only got the monthly figures for 2000 because I'd printed them off
18months
ago for another subject.
After a year or so, the monthly figures on the web site are compressed into
yearly, and comparison is difficult, unless one has squirreled the original
away!
We've seen this before haven't we?