Friday, May 05, 2017

How to Evaluate A Study: Folic Acid and Brain Development

Today’s lesson: how to judge a parenting study in the news. It happens all the time. You read about a promising new study, maybe the latest brain research or bullying survey and wonder how much trust to put in the findings. Are the results reliable? Is the study a sound one? I asked myself these same questions this morning when reading about a new UK study linking folic acid in pregnancy to children’s later emotional development. In other words, a perfect chance to illustrate how to quickly evaluate a new study in the media. I’m going to show you the same article I read on Science Daily, enough of it to get a sense of the study. If you have time, go read the brief article first. As much as I'd like to, I can't copy the whole thing here. Check it out, starting with the title and two sub-titles, all in bold:
Psychological benefits for kids when moms keep taking folic acid 
Taking folic acid supplements throughout pregnancy may improve psychological development in children 
Children's emotional intelligence improved if mums take folic acid supplements throughout pregnancy. 
Taking folic acid supplements throughout pregnancy may improve psychological development in children. 
.....[the researchers] will present their study to the Annual Conference of the British Psychological Society in Brighton.... 
The researchers asked the parents of 39 children, now aged seven, to answer questions about their child's personality...Within this group 22 mothers had taken the supplement throughout their pregnancy while the other 19 took it during the first three months only. 
...children whose mothers took the supplement throughout pregnancy demonstrated higher levels of emotional intelligence and resilience. Additionally, the level of folic acid in mother's blood towards the end of pregnancy was a good predictor of children's resilience and emotional intelligence.
My red marks point out some key details, as if you didn't notice. Let’s break it down, starting with the title.

Title: Psychological benefits for kids when moms keep taking folic acid.

Sounds like the study proved folic acid caused the benefits.

Sub-title: folic acid…may improve psychological development…

Wait, may improve? We don't know for sure?

Second sub-title: emotional intelligence improved if

Now it sounds more like the study showed FA did cause resilience and EI.

This is the classic Causal Flip Flop. Is it or isn’t it a study that could demonstrate FA caused more resilience and EI? You need to know this. You need this information to fully evaluate a study. It matters greatly. I cannot overstate this point.

Let’s continue. See if we can figure it out.

Procedural Details: The researchers asked the parents of 39 children, now aged seven, to answer questions about their child's personality…

Parents reported all the personality data about their children. Not good. Better if there were reports from another party, e.g. teacher reports. Best, if they collected a few more objective reports. 

39 kids. This is a very small study. A pilot study. Before the bigger one.

Age 7. Okay so researchers leapt more than 7 years from pregnancy to collect parental reports. What happened during that time? Could there be any intervening variables?

Causal Details?: Within this group 22 mothers had taken the supplement throughout their pregnancy while the other 19 took it during the first three months only.

It would be tempting to assume the researchers randomly assigned some mothers to take FA for the whole pregnancy, and others just 3 months. But this article does not specifically mention random assignment.
Analysis showed that children whose mothers took the supplement throughout pregnancy demonstrated higher levels of emotional intelligence and resilience. Additionally, the level of folic acid in mother's blood towards the end of pregnancy was a good predictor of children's resilience and emotional intelligence.
This pretty much confirms this is not an experiment. Researchers did not randomly assign the women. Because we read that FA is a good predictor in the final paragraph and not that it caused or had an effect – I am almost certain, given this information, we have a survey and not an experiment. 

But earlier in the article we have this comment from one of the researchers:
"There is evidence that folic acid supplements taken during the first three months of pregnancy can have beneficial effects on children's brain development. We wanted to investigate whether continued supplementation throughout pregnancy had any additional effects."
So we have the researcher talking about effects. Not good. Annoying. 

Other Explanations: None offered, remarkably. Why else might folic acid through pregnancy be linked to better resilience and EI? Better socio-cognitive skills, as we psychologists call them? Can you think of why moms who take their pregnancy supplements might have children with more such skills? Who are the pregnant women who take all their supplements? See, this is why it matters that the study is not randomly done. The women who stuck it out also might have a host of other such behaviors and skills that enable them to raise more resilience kids. A genetic component is likely also involved in these complex socio-cognitive behaviors. All the more important to know whether this is an experiment. 

Is it Published?
....will present their study to the Annual Conference of the British Psychological Society in Brighton.
No, it is not yet published. It will be presented at a conference, and is coming to us because the conference hosts (the British Psychological Society) have sent press releases via Eureka, a news service and also to Science Daily. It is too small a study to be published in a good journal.

Brain Development:
This is the nitty gritty. The researcher mentioned brain development. Yet this study did not assess brain development. No brain studied here. Only kids reported behavior. There were no fancy fMRI brain scans. There were not even cognitive assessments. In fact nothing to show the progression of neural development. This is all speculative. The researchers appear to think folic acid creates changes in the developing brain of fetuses, and that this sets a child up for enhanced brain development, that later lead to better socio-cognitive development. Seven years later. That is totally possible. However it is still uncertain, speculative. You get it.

My Conclusion:
We have a small study. Interesting. Preliminary. Potentially valuable but still highly speculative, especially uncertain in terms of whether FA caused the supposed benefits (via enhanced brain development). There is no direct link here. I can’t say for certain that women were randomly assigned but I assume they were not, due to a few clues in addition how research typically happens. Pregnant women are usually not randomly assigned in any study. I suspect the folic acid data was part of a larger project, data collected to investigate a number of different links and issues – this is how many maternal health studies happen. I wonder what other measures the researchers had access to but 1) did not report in their study and 2) they tested but did not come out significant and thus were left out of the study. It might even be that the same researchers were the ones who showed the purported “effects” of folic acid early in pregnancy. There is a link, it needs to be clarified and likely will be in future research. There seems to be other evidence of a link, according to this article. That is a good sign. You could check it out if you have time. How great if folic acid did impact these critical skills. My guess, if it does have a real effect, it is likely modest. But we will see. 


So how'd you do? Let me know if this was a helpful exercise. I could do this from now until forever. I love doing this but am not sure of the appetite out there.

Monday, April 17, 2017

Exaggerated Benefits of Breastfeeding

“There are countless medical, emotional, and economic benefits of breastfeeding…”
The American Academy of Pediatrics, April 2017

The benefits of breastfeeding are so plentiful they can’t be counted. Countless. Do not fall for this spin in the new clinical report issued this month by the American Academy of Pediatrics. Although “countless” the AAP still managed to rattle off a list of purported breastfeeding benefits to try to dazzle pediatricians into believing the benefits are stronger and better than they truly are.

The AAP experts are no longer interested, if they ever were, in quantifying the purported benefits. They certainly don’t like to take measure of the size of the benefits. Like telling you the number of ear infections you can prevent by breastfeeding for 6 months. They do not want moms to know it is less than one. As it turns out, breastfeeding benefits are relatively moderate and short-term. But that does not make anyone want to breastfeed let alone for one year, exclusively for 6 months.

I won’t even comment today on the other questionable language and claims in the new AAP report, including “optimal cognitive development.” 

Parents deserve better information. They don’t deserve “countless” benefits of breastfeeding. A respected pediatric organization should not spin health information. Period.