Hear, hear!  I still think EVERY lactation consultant should be required to take a course in statistics and a course in research methods.  When in practice, most practitioners rely on experience, not evidence, in my observation of 36 years in healthcare and most of that in some maternal-child field.  If it worked for the last patient, maybe it'll work for this one.  Placebo effect, Hawthorne effect, self-fulfilling prophecy, so many possibilities, it is daunting sometimes to tease out truth and value.  What Susan says here is very appropriate to consider.   Unless good studies are designed that include a valid set of subjects, proper cohorting, non-biased review of results, etc., we are all relegated to the place of "what happened last time."   Breastfeeding has to be taken as a serious human activity that should be the BASE, not the exception.  Until we get a control population of NORMAL breastfeeding occurring, all studies seem to be somewhat off.  I still see physicians in popular magazines in my area equating breast milk or formula, solid foods from 4-6 months (not 4 months for formula-fed, 6 months for breastfed) etc.

-----Original Message-----
From: Lactation Information and Discussion [mailto:[log in to unmask]] On Behalf Of Susan Burger
Sent: Friday, October 30, 2009 8:23 AM
Subject: Re: Confirmation bias for an off topic subject

Dear all:

I think this might be the straw that broke the camel's back.  I am quite tired of seeing "confirmation bias" used to shore up one's own particular beliefs on Lactnet.

We all should have sufficient education to understand the basic principals of science.

Here's the definition of confirmation bias:

* confirmation bias: the tendency to interpret new information in such a way that confirms one's prior beliefs, even to the extreme of denial, ignoring information that conflicts with one's prior beliefs

Association does not prove causation and just because two events happen at the same time does not mean they are related.  Nora Ephron used this faulty logic to claim in a New York Times piece that because breastfeeding has increased and so had food allergies, breastfeeding caused allergies.  That sort of thinking has perpetuated many a false fear or unwarrented and sometimes harmful treatments.

Here's a list of excellent criteria to judge causality from an article on smoking.  Despite the fact it was written in the 1960s, it was reprinted in 2005 because of its excellence:

* Strength of the relationship* Consistency* Temporality* Temporality* Biologic gradient (dose response)* Experimental evidence* Plausibility* Coherence* Probability* Analogy

Source:  Sir Austin Bradford Hill.  The Environment and Disease:  Association or Causation?   January 14, 1965,  Section of Occupational Medicine.  Proceedings of the Royal Society of Medicine.  Bulletin of the World Health Organization.  Oct. 2005, 83 (10): 796-798.

If you wanted to find out whether or not something was related to a decrease in milk supply, you would need to see what proportions of women have a decrease in supply among those that have the condition or were subjected to a treatment and among those who are not,

As for milk supply, I have had countless cases of low milk supply when there was no one specifically identifiable cause as well as cases when I have explored potential causes with the mother only to find out that our local breastfeeding medicine specialist was able to tease out a cause that wasn't divulged with the initial inquiries.  The satate of knowledge about physiological causes of low supply is incredibly poor for two reasons a) research on this topic was neglected during the bottle feeding years, and b) the disruption in support for breastfeeding has not recuperated to the point that infant feeding has returned to normal.  Most of what we see is due to insidious, sometimes subtle and sometimes overt behaviors that undermine supply.

I don't mind when people speculate on Lactnet as long as it is clearly identified as such.  But, when I see repeated episodes of "fishing expeditions" as we call them in epidemiology to only collect the information that you want to support your own view I have to say that I am exceedingly disappointed. If you do not also include evidence that might disprove your view, you are not collecting evidence, you are engaging in confirmation bias. And in the grand scheme of things it does not matter to me which side of an issue one is on when one engages in such practices.  It is simply bad science and bad science helps no one.  If you then go on to use information collected in this manner to promote a cause, ignoring any counter evidence, you are then engaging in propaganda.


Sincerely


Susan E. Burger, MHS, PhD, IBCLC

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