There she goes again.
Melissa Bartick has published yet another paper, Suboptimal breastfeeding in the United States: Maternal and pediatric health outcomes and costs, claiming to demonstrate that breastfeeding saves lots of lives and billions of dollars.
[pullquote align=”right” cite=”” link=”” color=”” class=”” size=””]Bartick’s claims are based on the assumption that correlation is causation. It’s not.[/pullquote]
Bartick continues to model the impact of breastfeeding rates on death rates and healthcare spending while utterly ignoring the real world data on the impact of breastfeeding rates.
In this paper, she created a Monte Carlo simulation:
This is the first comprehensive analysis of the health and economic burdens of suboptimal breastfeeding rates in the industrialized world, using Monte Carlo simulation models to include maternal and pediatric disease in a single study.
Her simulation predicted the following:
Annual excess deaths attributable to suboptimal breastfeeding total 3,340 (95% confidence interval [1,886 to 4,785]), 78% of which are maternal due to myocardial infarction (n = 986), breast cancer (n = 838), and diabetes (n = 473). Excess pediatric deaths total 721, mostly due to Sudden Infant Death Syndrome (n = 492) and necrotizing enterocolitis (n = 190). Medical costs total $3.0 billion, 79% of which are maternal. Costs of premature death total $14.2 billion. The number of women needed to breastfeed as medically recommended to prevent an infant gastrointestinal infection is 0.8; acute otitis media, 3; hospitalization for lower respiratory tract infection, 95; maternal hypertension, 55; diabetes, 162; and myocardial infarction, 235. For every 597 women who optimally breastfeed, one maternal or child death is prevented.
Or, as Bartick told WBUR:
The most surprising thing is that breastfeeding is even more of a maternal health issue than a children’s health issue. It has a bigger impact in terms of medical cost and a bigger impact in terms of lives saved. And most of that impact is derived from encouraging women to breastfeed as long as they can for each child.
Of note, Bartick has already dialed back substantially from claims made in previous papers, in 2010 and in 2013. It seems that even she recognizes that her previous claims were exaggerations.
Unfortunately, with the exception of nectrotizing enterocolitis, her conclusions still have no basis in reality.
Why does Bartick keep modeling the theoretical impact of breastfeeding instead of investigating the actual impact of breastfeeding? Because the actual data, based on 40 years of dramatically rising breastfeeding rates, doesn’t show much benefit at all. In other words, breastfeeding saves far more lives and money in theory than in requity.
There’s a simple reason why Bartick continues to find that benefits of breastfeeding are so much greater in theory than in reality: her theoretical models are based on a desperate wish that correlation is causation. But as we know from Statistics 101, correlation is NOT causation.
Bartick ought to know, too. The WBUR reporter asked her whether her numbers are reliable. She responded:
The numbers themselves are derived from other studies but we took the best studies and used conservative estimates … the ASSUMPTION is that there is a causal relationship between breastfeeding and these diseases based on the published studies.(my emphasis)
So if her assumption is wrong, her numbers are wrong. As they say in statistics: Garbage in, garbage out.
Yes, breastfeeding has an association with heart disease, breast cancer and diabetes. But lots of things have associations with the same diseases, including socio-economic status (SES).
We know for a fact that mothers of higher SES are more likely to breastfeed. Breastfeeding, therefore, could be a proxy for socio-economic status. The purported benefits of breastfeeding aren’t caused by breastfeeding; they’re caused by wealth and access to healthcare. That may be why the dramatic increase in breastfeeding rates that has occurred in the US over the past 40 years has not had any noticeable impact on maternal or infant death rates.
In other words, there’s absolutely no evidence for Dr. Bartick’s ASSUMPTION that not breastfeeding causes disease in women or that breastfeeding prevents disease. Why? Because correlation is not causation.
Dr. Bartick makes the same error with pediatric disease. The one exception is nectrotizing enterocolitis (NEC) in premature infants. There is strong evidence that feeding premature infants breastmilk instead of formula can prevent NEC. The relationship with SIDS is more tenuous.
Of note, Bartick has completely dropped the claims from her 2010 paper that breastfeeding prevents atopic dermatitis, childhood asthma, childhood leukemia, type 1 diabetes mellitus, and childhood obesity. In other words, she implicitly acknowledges that many of the assumptions she made in that paper were wrong.
Sadly, many of the assumptions she makes in this paper are equally wrong.
The WBUR reporter asked Bartick:
There have been several studies and recent books, notably “Lactivism” by Courtney Jung, that suggest the benefits of breastfeeding have been overstated. In a similar vein, Dr. Amy Tuteur argues that there’s just too much “bressure” on women to breastfeed. Obviously, you disagree, but what’s your response to the breastfeeding backlash, in general?
Bartick tries to side step:
We know that most women in the U.S. actually want to breastfeed. Over 80 percent of U.S. women initiate breastfeeding. Yet, data from the CDC show that 60 percent of women aren’t meeting their own breastfeeding goals, even if those goals are modest. So, what we are really seeing is that women are not getting the support they need to breastfeed…
But women claim they want to breastfeed because people like Bartick insist that there are dramatic benefits to breastfeeding. Bartick herself is a source of “bressure” and it is disingenuous in the extreme to suggest that the pressure to breastfeed comes from women themselves.
Bartick’s latest paper is yet another deliberate addition to the “bressure.” The reality is that the benefit of breastfeeding in industrialized countries is trivial.
So Bartick ignores reality and takes refuge in theory.
