I've had a read of this paper.

Colen, C.G., Ramey, D.M., Is Breast Truly Best? Estimating the 
Effects of Breastfeeding on Long-term Child Health and Wellbeing in 
the United States Using Sibling Comparisons, Social Science & 
Medicine (2014), doi: 10.1016/j.socscimed.2014.01.027.

It's a worthwhile topic - take siblings who differ in how they were 
fed as infants, and see how the long term outcomes compare.

But I do think it's badly executed.

The statistical presentation is mystifying. The authors need to read 
Ben Goldacre's book Bad Science which has a useful chapter on making 
findings intelligible.

Having said that, the exercise is a constrained by 2 major facts:

* the bf info is restricted to ever breastfed, and how long with any 
breastfeeding in weeks ie no information on whether the bf was 
exclusive, predominant, minimal...

* the outcomes are selected from a longitudinal cohort study of 
children aged between 4 and 14 and are body mass index, obesity, 
asthma, hyperactivity, parental attachment, behavioral compliance, 
reading comprehension, vocabulary recognition, math ability, memory 
based intelligence, and scholastic competence

That list is a strange one. Who of us on this list would expect to 
see a difference in BMI/obesity because of any breastfeeding lasting 
into the early teens - family influence  (obviously strong, for 
siblings) and other environmental influences would overwhelm any 
'breastfeeding factor'. Has anyone even hypothesised that 
hyperactivty (defined how? As ADHD?) is affected by any 
breastfeeding? Behavioural compliance? What's that on the list for?

The sample is reduced to 1,773 children by the time the cohort is 
reduced to 'discordant siblings' -  I would be unsure if the survey 
is powered enough to reveal significant findings, anyway.

Not impressed.

Heather Welford Neil
NCT bfc, tutor, UK
-- 

             ***********************************************

Archives: http://community.lsoft.com/archives/LACTNET.html
To reach list owners: [log in to unmask]
Mail all list management commands to: [log in to unmask]
COMMANDS:
1. To temporarily stop your subscription write in the body of an email: set lactnet nomail
2. To start it again: set lactnet mail
3. To unsubscribe: unsubscribe lactnet
4. To get a comprehensive list of rules and directions: get lactnet welcome