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

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