Imagine a study that compared in hospital blood transfusion rates to death rates. What would you conclude if that study found that people who received blood transfusions were more likely to die than those who did not?
Would you postulate that blood transfusions caused deaths? Would you recommend that blood transfusions be withheld? Of course not!
You would almost certainly recognize the obvious: people who received blood transfusions are likely sicker those who did not and therefore the two groups can’t be compared directly. You would understand that withholding blood transfusions from those who need them would lead to more deaths not fewer.
A new study claiming to show that in hospital formula supplementation reduces breastfeeding duration is a joke.
That’s why a new study that claims to show that in hospital formula supplementation reduces breastfeeding duration is such a joke. It’s yet another example that breastfeeding research sucks.
The paper is In-Hospital Formula Feeding and Breastfeeding Duration by Marcia Burton McCoy, MPH, IBCLC, Pamela Heggie, MD, IBCLC.
Here’s what the authors think they found:
Hazard ratios (HR) for weaning increased across time. In the first analysis, the HR across the first year was 6.1 (95% confidence interval [CI] 4.9–7.5), with HRs increasing with age (first month: HR = 4.1 [95% CI 3.5–4.7]; 1–6 months: HR = 8.2 [95% CI 5.6–12.1]; .6 months: HR = 14.6 [95% CI 8.9–24.0]). The second, more conservative analysis revealed that infants exposed to IHFF had 2.5 times the hazard of weaning compared with infants who were exclusively breastfed (HR = 2.5; 95% CI 1.9–3.4).
CONCLUSIONS: IHFF was associated with earlier weaning, with infants exposed to IHFF at 2.5 to 6 times higher risk in the first year than infants exclusively breastfed. Strategies to reduce IHFF include prenatal education, peer counseling, hospital staff and physician education, and skin-to-skin contact.
Here’s what they actually found: absolutely NOTHING!
Why is the study a joke? Because it fails to fully account for the fact that mothers whose babies need in hospital supplementation may have insufficient breastmilk. The two groups of infants being compared are not comparable and therefore no conclusions can be drawn.
The authors did recognize that — contrary to the beliefs of many lactation professionals — insufficient breastmilk is both real and common. But they did not adequately take that reality into account.
The authors made four assumptions:
1. On the basis of early weight loss nomograms for exclusively breastfed newborns, a maximum of 5% of infants experienced weight loss ≥ 10% because of primary lactation failure.
2. All cases of primary lactation failure were detected by excess weight loss.
3. All infants with excess weight loss were given formula rather than the mother’s expressed milk or pasteurized donor human milk.
4. Those with excess weight loss had the shortest durations of breastfeeding of all infants exposed to IHFF.
Therefore:
In this analysis, we excluded the 5% of IHFF infants with the shortest breastfeeding durations before matching.
Using those assumptions, the “risk” of in hospital formula supplementation leading to weaning was cut dramatically from 6.1 to 2.5.
But most cases of insufficient breastmilk are NOT diagnosed immediately. It can take days or even weeks for insufficient breastmilk to become apparent.
Furthermore, the incidence of insufficient breastmilk in the first week or so after birth is up to 15%, much higher than the 5% that the authors assumed. As a result, they failed to fully account for breastfeeding complications. Therefore, their results are worse than meaningless.
That’s hardly surprising because most breastfeeding research is like bad drug company research; it is impaired by conflicts of interest. It uses statistically illiterate methods to demonstrate meaningless ”benefits” and reach the predetermined conclusion that we should be buying more of whatever the breastfeeding industry is currently selling.
