Newborn racial concordance debunked

Random samples matter

On August 20, 2020, CNN had this to say in their article, Black newborns more likely to die when looked after by White doctors:

The mortality rate of Black newborns in hospital shrunk by between 39% and 58% when Black physicians took charge of the birth, according to the research, which laid bare how shocking racial disparities in human health can affect even the first hours of a person’s life.

The study published in PNAS, Physician-patient racial concordance and disparities in birthing mortality for newborns, was published three days earlier. The Washington Post took five months to report on this study in their article Mortality rate for Black babies is cut dramatically when Black doctors care for them after birth, researchers say. (1/13/2021) The Guardian was on it the same day the paper was published with Black babies more likely to survive when cared for by black doctors—US study. (8/17/2020) Etc.

Before we get to what the study missed, it is worth noting the rhetoric in the paper itself. A few quotes from the paper:

These results underscore the need for research into drivers of differences between high- and low-performing physicians, and why Black physicians systemically outperform their colleagues when caring for Black newborns.

Taken with this work, it gives warrant for hospitals and other care organizations to invest in efforts to reduce such biases and explore their connection to institutional racism (50, 51).

Furthermore, it serves as an important call to continue the diversification of the medical workforce (48).

As you can see, the authors have a particular point of view. Personally, I don’t think this is appropriate for a scientific paper and suggested inherent bias in the researchers. Well, it turns out they missed something.

Now, before I say more, just as we shouldn’t jump to conclusions with the first paper, we shouldn’t conclude that the follow-up paper is the final say, but they do seem to have clearly debunked what I’ll call the newborn racial concordance hypothesis (Black newborns do better with Black doctors).

The follow-up paper in PNAS, Physician-patient racial concordance and newborn mortality (9/16/2024), has this to say:

We find that the magnitude of the concordance effect is substantially reduced after controlling for diagnoses indicating very low birth weight (<1,500 g), which are a strong predictor of neonatal mortality but not among the 65 most common comorbidities. In fact, the estimated effect is near zero and statistically insignificant in the expanded specifications that control for very low birth weight and include hospital and physician fixed effects.

In other words, White doctors dealt with more low birth rate Black newborns, below 1,500 grams, than Black doctors. This was enough to explain the mortality difference—the fact that there was higher mortality of Black newborns attended by White doctors. The paper does not speculate why White doctors end up with a disproportionate number of low-birth-rate Black newborns.

A key summary from the article (bold mine)

In other words, the newborns attended by White and Black physicians are not random samples. Black newborns with a very low birth weight are disproportionately more likely to be attended by White doctors than by Black doctors. Those newborns are also more likely to have a low chance of survival. The exclusion of the very-low-birth-weight variable from the regressions then suggests that, on average, Black babies attended by White doctors will have poorer outcomes than Black babies attended by Black doctors. But this effect may have little to do with racial concordance. It can instead arise because Black newborns attended by White doctors are more likely to have a vulnerability closely linked to mortality.

If samples aren’t random, nothing else after that has any meaning. The original paper missed this. I doubt this was on purpose as mistakes happen, but their rhetoric at the end of the paper should at least make someone be a little skeptical of the result and not jump to conclusions about racism, etc.

To be fair, the original study did have this to say (bold mine): “First, we are unable to observe the mechanism that is driving the observed result, or the selection process of the physician.” In other words, they had no idea why there was a difference yet still went on about racial issues, and the media picked up on it, ignoring this statement. In retrospect, this doesn’t pass the common sense test. Why would a Black doctor be better at caring for a newborn Black baby than a White doctor? Or vice versa, for that matter.

Returning to the follow-up paper, they had no rhetoric and ended by saying:

Our study shows how an important research design decision can yield an empirical finding of racial concordance in newborn mortality. Specifically, the influential research in ref. 1 did not control for the impact of very low birth weights (i.e., under 1,500 g) on newborn mortality. Although these types of births are rare, they occur more frequently in the Black population, and they account for a very high fraction of mortality. It turns out that a disproportionately large number of Black newborns with very low birth weights are attended by White physicians. We show that once we control for the impact of very low birth weights on mortality, the estimate of the racial concordance effect is substantially weakened and becomes statistically insignificant in models that account for other factors that determine newborn mortality.

Now, it is possible that the second paper missed something else, and they do mention the fact that there are more frequent low birth rate newborns in the Black population. Certainly something worth understanding more thoroughly. We also don’t know why White doctors end up with a disproportionate number of low-birth-weight Black babies.

The morale of the story here is to not jump to conclusions every time a new study comes out. Note it, but wait. Further, if the study confirms your view of the world, wait even longer. My concern is that the jumping to get the scoop by The Guardian, CNN, and the Washington Post does more harm than good, and, in fact, they may very well ignore the new study and never look to correct the record. Even if they did correct the record, most people will still remember the overall theme of the first paper and the media framing of racism. If you find follow-ups in the media, then let me know in the comments.

Please share and like

Sharing and liking posts attracts new readers and boosts algorithm performance. Everything you do is appreciated.

Comments

Please point out if you think something was expressed wrongly or misinterpreted. I'd rather know the truth and understand the world than be correct. I welcome comments and disagreement. We should all be forced to express our opinions and change our minds, but we should also know how to respectfully disagree and move on. Send me article ideas, feedback, or other thoughts at briefedbydata@substack.com.

Bio

I am a tenured mathematics professor at Ithaca College (PhD Math: Stochastic Processes, MS Applied Statistics, MS Math, BS Math, BS Exercise Science), and I consider myself an accidental academic (opinions are my own). I'm a gardener, drummer, rower, runner, inline skater, 46er, and R user. I’ve written the textbooks R for College Mathematics and Statistics and Applied Calculus with R. I welcome any collaborations.