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Maternal death rate problems in North Carolina

Somebody named Jerrod writes:

I though you might find this article [“Black moms die in childbirth 3 times as often as white moms. Except in North Carolina,” by Julia Belluz] interesting as it relates to some of your interests in health data and combines it with bad analysis and framing.

My beef with the article:

1) a 40 percent decrease in the black maternal mortality rate paired with an over 100 percent increase in white maternal mortality rate is presented as a policy success.

2) the author wants you to think that white maternal mortality has stayed the same (with the first figure) and then elides over the dramatic increase in North Carolina’s white maternal mortality rate by saying that it mirrors the recent increase in over white mortality.

3) the two figures have different time scales.

4) Its thesis (“Ultimately, North Carolina is saving more lives by focusing on income, not race”) is not supported by the data.

For the following, I’ll assume that no government action is a policy response. I looked at the Vital Records for NC to get the number of live births for each race category and then multiplied the percentage of maternal deaths per live birth by the number of live births. The 1999 vital records only had data for “whites” and “minorities”. The numbers presented assume all minorities in NC in 1999 were black (which would weaken any of my conclusions). The maternal mortality rates are from the article.

Even the difference between 1999 deaths and 2013 deaths doesn’t support the conclusion that government policy saved lives (keep in mind that this is during a time with falling fertility). The last column just takes the difference between the 2013 hypothetical deaths in the second to last column and the actual deaths in 2013. While every death is important, the article also glosses over the fact that these are small magnitudes.

Don’t take this as a slam on Belluz—these things are challenging to report—it’s just good to get multiple perspectives on this sort of thing.


  1. Corey says:

    It seems to me that graphing full posterior densities for smoothly time-varying rates along with the data would help with the appropriate interpretation of these data.

  2. oncodoc says:

    Maternal deaths are among the saddest, most bitter events in medicine. When we look at these numbers we must see beyond statistics and envision a young woman who along with her family is expecting the joyous arrival of a new soul and instead loses her own life. The maternal mortality rate in first world countries is in single digits; seeing a rate of 24-25 in North Carolina is troubling no matter how one slices it.

    • This is so true. All the more reason we should be very upset with the fact that overall the maternal death rate increased!!!!!

      Black people are about 22%, and White 71% of North Carolina, which suggests overall at the beginning the rate was:

      (38.9*.22 + 11.2*.71)/(.93) = 17.8 per 100k

      and at the end, since the rates are both 24, it’s 24/100k

      or a 30% increase overall since 1999 (to first order, ignoring differences in fertility and population percentage changes and other secondary issues)

      Whatever NC is doing, it’s doing it wrong, and claiming victory!

      • Anoneuoid says:

        Whatever NC is doing, it’s doing it wrong, and claiming victory!

        If the goal is “equality” rather than low mortality rates it would make sense. It is probably easier to raise the mortality rate of the rich/privileged than lower it for the poor/disadvantaged.

      • Jay says:

        “Whatever NC is doing, it’s doing it wrong, and claiming victory!”

        That conclusion is not supported by the evidence. To claim that what NC is doing is wrong you would have to show that NC white maternal mortality has increased more than other states after adjusting for age, income, and potentially other variables.

        All we can really say is that there is has been a surprising drop in black mortality. Maybe this is related to the Medicaid program the author mentions, maybe not, we can’t really say. It seems reasonable that a Medicaid delivered program would reduce black maternal mortality since black make less than white on average.

        The key piece of data I would like to see is the change in white maternal mortality for the Medicaid-eligible population. I have no earthly idea why this data is not readily available (and if it is then why on earth didn’t Belluz report on it?).

    • Harriette M Seiler says:

      A moving response. Reminds me of the quote about statistics are people with the tears wiped away.

      I hope you are a member of Physicians for a National Health Program

  3. Jerrod says:

    I will also say there are a few other issues with Vox’s (and my) analysis. One would ideally pool years (or at least have a running average) of the maternal mortality since, as I mentioned, the numbers (while higher than other developed countries) are still small. Also, one thing I didn’t mention: the author wants to associate the decrease in the black maternal mortality to how NC Medicaid treats mothers, but the date at which the effective policies were put into place are never mentioned. I would think that the listed treatments and tests for the expecting mothers would decrease maternal mortality, but if you want to make a causal claim, you should probably put in the date at which those policies were put into place.

  4. Elin says:

    I think that, once again, we need to consider age adjustment. First, nationally the number of births to teen agers has fallen dramatically, most likely due to the increase popularity and availability of long term contraception. I believe that Guttmacher has published data on this which I’ll try to find.
    Second is, of course, the increase in older women giving birth, not just as a proportion because the number of teens has gone down, but because of changes in both fertility treatments and age at first marriage. Not to mention the cultural changes that have made it socially okay for single older white women to have children.

    • Great points. I think a first quick and simple way to look at this would be to take the rate in NC and divide by say the average rate in the surrounding southern states. If demographics such as age at first conception, or the like are changing, to first order they’re probably changing in similar ways in other nearby states. If there’s a policy difference in NC, we should see it in the relative measure.

  5. Jay says:

    At first, I wanted to come to the defense of Belluz, in part because Jerrod’s critique just didn’t seem that insightful. But the more I think about it, the more I think Belluz is in the wrong here, in a major way.

    I think the article is problematic for most of the reasons stated here, but what’s really missing is curiosity – namely curiosity about what happened to the maternal mortality rates for the Medicaid-eligible population, in particular poor whites. That would give us a more accurate assessment of the success (or failure) of this program than the racial breakdown (Please note that this is not to discount the very real racial disparities in health care. Frankly, a lot of people who criticize articles like this are doing it just to satisfy their craving to be politically incorrect on the Internet – I am not one of those people).

    Along these lines it would be interesting to see the change in maternal mortality broken down by SES, race, and married status – that could provide some hints as to what’s really going on.

  6. Julia Belluz says:

    These are good and valid criticisms. I am going to update the post to address some of them. Thank you for taking the care to engage in the story.

    • Julia, it might also be worth looking into why both the black and white graph fluctuate so dramatically from year to year. If they jump around more than other states, then perhaps something is amiss with NC’s data? Even if the data is correct, it may be hard to say there’s any meaningful trend going on given that the black graph does a such a dramatic 180-degree turn in 2006 and the white graph in 2009. Given this volatility, I think we could very well see the gap reopen dramatically next year…or even reverse itself.

      • gregor says:

        The rate ranges from ~16 to 60, in multiple instances doubling or dropping in half in a single year. In terms of actual deaths, assuming 30,000 live births, we’re talking about, what, 5-18 deaths in given year? Even with impeccable data, I would expect high volatility with such small counts. Using Jarred’s number of 11.26 expected deaths using the 1999 rate, 2013 is only about 1 SD off (assuming binomial/poisson). Yet that drops the mortality rate from 38.9 to 24.3.

        • Elin says:

          Really the graph at least shows no trend at all in terms of White rates, it just shows that in 2013 there was an unusually high number. Visual inspection does not show any long term pattern. 2010 – 2012 are basically identical to 1999. So the question there is was there anything special that would explain the uptick in 2013. Likewise the compelling question about the Black rates were so high in the early 2000s.

  7. Juju says:

    Sometimes the discrepancies have to do with the definition of maternal mortality at the time—deaths in the first year after a birth, and some will only report deaths within the first month. What is reported and how it is recorded in each state varies, and especially internationally. Sometimes it’s comparing apples to oranges to fish.

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