billo said: " Dude, read the paper. What is the referent group for this
OR calculation?
It is the Herbicide applicator group! That's my point. ORs do not
exist in a vacuum. An odds ratio means that one group's odds are
greater than another group's odds. In this article, the group of
pesticide applicators who included glyphosate have an increased
odds ratio compared to herbicide applicators who include
glyphosate. In other words, the paper states that people who
apply pesticides+herbicides+fungicides are at greater risk
than those who apply herbicides alone.

It does not address those who apply herbicides alone compared
to people who do not use herbicides, and that is how you
are interpreting it.

If you have a quote that shows that they are using a different
referent group than the one they say they are using, trot it
out.

As I stated, it's not surprising that the addition of Roundup to an
overall exposure of numerous other pesticides may result in increased
morbidity. That kind of syndergism is pretty common, and there
is a decent biological explanation. However, the referent group
in this study *also* used glyphosate, and any conlcusion from it
that glyphosate alone is toxic when used as directed is not
supported by this study.

If you have one sentence that states that the referent group
for the OR calculation you quote is not the herbicide group,
I'd love to see it.

The paper does not show what you claim it shows."

H. Kuska reply: Billo, please go back to table 6, that is where the referent
herbicide group (that you refer to) was utilized (8 out of 118). The
authors do not have to state what referent group they are using for each
Odds Ratio calculated, it is defined by definition. If you are unwilling to
accept this by trusting the authors, do the calculation yourself for the
similar phosphine case (see below).

Readers of this thread can check the calculation themselves by using the
following program:
http://www.ahp.niu.edu/oleckno/Sampl...OddsRatio.html

The raw information on page 445 is:

"Altogether 3.8% of children whose parent used phosphine versus 1.5% of
those who did not use the fumigant had adverse central nervous system or
neurobehavioral sequelae (OR = 2.5; CI, 1.22-5.05). Similarly, use of the
phosphonamino herbicides (glyphosate, Roundup) was overrepresented in the
adverse birth and development effect group. Forty-three percent of the
children (6 of 14) who had parent-reported ADD/ADHD used phosphonamino
herbicides (OR = 3.6; CI, 1.35 - 9.65)."

The above is the odds ratio data that appears in the abstract for
glyphosate. Unfortunately for this discussion, they do not give sufficient
raw data in the body of the paper to check this number; but they do for the
parallel phosphine case which they treat in detail (for the readers of this
thread, it is common in articles, to save space, to only treat in detail one
case if the others are similar).

For phosphine the calculated OR was reported as 2.48 with a CI of 1.2-5.1.
Unfortunately, the raw data is given on page 445 as percent. To use the
above program per cent has to be changed to whole numbers. This will have a
significant effect on the CI and also possibly lead to small round off
errors in the OR but will give you a ballpark figure to show that they used
the correct referent group.

a = 3.8% which when converted to whole numbers is 38.
b = 100% - a = 96.2% which converted is 962.
c = 1.5 % which when converted to whole numbers is 15
d = 100% - c = 98.5% which converted is 985

The calculated OR is 2.59 and the 95% CI is 1.42-4.75.

Please let me know if there are any points that you need clarified.

Henry Kuska, retired

http://home.neo.rr.com/kuska/