Subject: | |
From: | |
Reply To: | |
Date: | Thu, 28 Sep 2006 15:24:35 -0600 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
Lynnette Hafken writes:
>http://www.slate.com/id/2150354/
>
>I am quoting the relevant part:
>
>The NNTs are astronomically high. Reasonable women might think that
>breast-feeding isn't worth the trouble-a conclusion that you don't
>want drawn if you're promoting breast-feeding at any cost."
Wow, this is wrong on so many levels, it is hard to know where to
start. First of all, they are casting breastfeeding as the
"experimental" "treatment" by using NNTs to compare it to not
breastfeeding. Breastfeeding is neither experimental nor a
treatment. I would be interested to know if the natural state is
ever considered the "experimental treatment" in any other NNT
calculations? ie, breathing clean air as the experimental treatment
vs. smoking as the norm? I am no expert on statistics but I would
bet that NNTs generated in this way are meaningless.
That said, I believe it is incorrect to say that NNTs would be
"astronomically high". There are many illnesses and conditions that
occur far more frequently in non-breastfed babies, such that the NNTs
would be small numbers. A glance at the literature and some quickie
calculations yield the following: the NNT for respiratory illness
would be 6.5; for wheeze related to early solids, 9; for ear
infection by 6 months of age, 3.5. Those are not "astronomically
high" by any definition. If I had all afternoon I could compile a
much more impressive list, but it's obvious right now that the Slate
article cannot be taken seriously.
Certainly if you combined *all* the things that artificially-fed
children are at greater risk of, then the combined NNT for *all*
outcomes would be ridiculously low. If we add in the increased
health risks for non-breastfeeding mothers, the cumulative NNT would
be even more miniscule.
(By the way, NNT = Number Needed to Treat to prevent one bad outcome.
If a treatment reduces the incidence of a bad outcome by 50%, then
the NNT is 2. Two people need to undergo the treatment in order for
*one* bad outcome to be prevented. If NNTs are small numbers then
the treatment appears to be worthwhile, whereas if the NNTs are very
large then it looks like it's not worth it to "treat" all those
people to avert one bad outcome.)
The Slate article has both the basis wrong (artificial feeding as the
norm) and the facts wrong (NNTs astronomically high). This doesn't
surprise me too much, unfortunately, as Slate has run some very
slanted anti-bfdg articles in the past few years.
Margaret
Longmont, CO
***********************************************
To temporarily stop your subscription: set lactnet nomail
To start it again: set lactnet mail (or digest)
To unsubscribe: unsubscribe lactnet
All commands go to [log in to unmask]
The LACTNET mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software together with L-Soft's LSMTP(R)
mailer for lightning fast mail delivery. For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html
|
|
|