Wednesday, November 4, 2009

U.S. lags further behind in infant mortality

The Centers for Disease Control (CDC) have released figures that show that infant mortality rates in the U.S. exceed many other countries in the world. In the latest CDC analysis, which uses 2005 data, the U.S. ranked a disappointing 30th. So much for our world-leading medical expenditures buying us better health outcomes.
The United States international ranking in infant mortality fell from 12th in the world in 1960, to 23rd in 1990 to 29th in 2004 and 30th in 2005. After decades of decline, the United States infant mortality rate did not decline significantly from 2000 to 2005.
Some have argued that infant mortality rates cannot be compared across countries because of differences in the ways that births are registered (some countries don't count very early or very low weight births as "live" births).

The CDC report acknowledges these differences but concludes
There are some differences among countries in the reporting of very small infants who may die soon after birth. However, it appears unlikely that differences in reporting are the primary explanation for the United States’ relatively low international ranking. In 2005, 22 countries had infant mortality rates of 5.0 or below. One would have to assume that these countries did not report more than one-third of their infant deaths for their infant mortality rates to equal or exceed the U.S. rate. This level of underreporting appears unlikely for most developed countries.
Even so, the detailed analyses in the CDC report focus on European countries, most of whom use the same reporting standard that the U.S. does, and limit the comparisons to mortality among infants with a gestational age of 22 weeks or more.

The CDC analyses indicate that
The main cause of the United States’ high infant mortality rate when compared with Europe is the very high percentage of preterm births in the United States.
However, the report also shows that the U.S. has one of the highest mortality rates for infants born at or near full term (after 36 weeks). For instance, the report compares births between the U.S. and Sweeden. If the U.S. had Sweeden's gestational age distribution, the U.S. infant mortality rate would be about a third lower than it is. However, even this adjusted birth rate would be 30 percent higher than Sweeden's. Put another way, differences in gestational age distributions account for two-thirds of the difference in infant mortality rates between the U.S. and Sweeden, but the remaining one-third is due to higher gestation-specific mortality rates in the U.S.


pino said...

Dave, as you posted this I was working on one of my own. As you mentioned, nation's report differently. The US reports all live births, the EU reports births after 22 weeks yet many of those nations don't even follow THAT guidline.

Further complicating the indicator is that the variation of types of births is not common across all the nations. For example, in the US, we have many many more premature births. And you touched on that. But looking even further, the US has more low birth weight births than other nations. The cause of low birth weight deliveries can seem to be attributed to factors not related to medical care delivery.

Does the US have a poorer IMR than other nations? Yup. Is that because we have a worse medical care delivery system? I don't think the numbers support that.

Dave Ribar said...


Your comment about reporting differences does not square with the CDC analysis (see Table 1). If I read the CDC analysis correctly, 2/3 of the EU countries use the same standard that we do; 1/3 do not.

Even so, in its detailed comparisons, the CDC also limits its analysis to births after 22 weeks.

In any case, the CDC concludes that reporting differences do not contribute much to the variation (although the mortality rate for very early and very small births is high, there just aren't that many of them to move the numbers).

The U.S. does have more premature births. However, the CDC analysis shows that even when you account for that, the U.S. still has a higher IMR.

Moreover, there is a health care component to early and low weight births. Mothers who do not get prenatal care in the first trimester have substantially higher risks of preterm and lw weight births. While there are behavioral components, you can't rule out health delivery components.

pino said...


You say that you can't rule out health delivery components. I wonder, do the statistics rule IN behavioral components?

I have long made claims that when normalized, the US ranks #1 in the world. I bet I'm wrong. But I would also bet that we are closer to #1 than to #30, 33 or 37.

Bubba said...

Are you still beating that particular dead horse of an argument?

Your analysis is no better than the first time you tried to spin this thing.

Here's a little more perspective about the false "infant mortality" meme you're so anxious to prop up:

"What does all this say about the state of maternity care in the U.S.? To this layman, it suggests that we’re pretty good at getting women pregnant who might otherwise not get pregnant. We’re also pretty good at delivering very pre-term or very sick babies, and keeping them alive, at least long enough to be counted as infant deaths rather than peri- or neo-natal deaths. It points out the racial and economic disparities in health and healthcare that persist in our country. It points out that we still aren’t very good at preventing premature births."

As far as the related meme of "low US life expectency", the information still doesn't jibe:

"If you've sorted the data in the dynamic table, you find that without accounting for the incidence of fatal injuries, the United States ties for 14th of the 16 nations listed. But once fatal injuries are taken into account, U.S. 'natural' life expectancy from birth ranks first among the richest nations of the world."

If your intent is to suggest that the nation would be better off having a system of nationalized universal or semi-universal health care, you and like minded purveyors of misleading or narrow minded information are not doing a particularly good job.

Dave Ribar said...


From the CDC report (first sentence), "Infant mortality is an important indicator of the health of a nation, and the recent stagnation (since 2000) in the U.S. infant mortality rate has generated concern among researchers and policy makers."

The link that you included doesn't seem relevant to the post, as I wasn't criticizing the quality of obstetric care.

The only "spin" was that our high-cost medical system (we spend about a third more per person than the next leading country and roughly double the OECD average) has considerable room for improvement.

While infant mortality rates in other countries are falling, the U.S. rate stagnated starting in 2000. Fetal mortality in the U.S. (the rate of still births) has also stagnated.

We would expect medical advances, better knowledge, and increasing medical expeditures to contribute to better outcomes, but they are not.

pino said...


No one denies that IMR is an "important indicator of the health of a nation." We are objecting to it being used as a proxy for an indicator of the medical care delivery system.

We utilize fertilization techniques that are allowing many many thousands of couple have children who might not otherwise been able to. Those pregnancies are at risk. Do you think that this practice is an indication of a poor medical system or a strong one? Set aside the moral implications of rolling the dice on children's lives.

Further, we could all forgo fruit and eat at McDonalds. This would also be an "important indicator of the health of the nation." Yet no one would consider it an implication of the medical care delivery system.

Dave Ribar said...


The infant mortality rate is not a "proxy" for the "medical care delivery system." Instead, it is an outcome from that system.

An analogy would be the very expensive education system, which has some gold-plated institutions that are the envy of the world but which also continues to produce some stunningly bad outcomes (high drop-out rates, kids that can't read or write, college graduates that can't read or write, etc.).

The medical system also has some awesome components, but it's also got many weaknesses that seem to contribute to bad outcomes.

I would put more stock in the "fertility treatment" argument if the IMRs were higher for middle- and upper-income families. But the IMRs are highest among groups with the biggest barriers to health care.

Pino said...

"I would put more stock in the "fertility treatment" argument if the IMRs were higher for middle- and upper-income families."

I certainly don't mean to imply that fertilization treatments are the sole cause for higher IMRs in the US. I am saying that it is a cause. Along with LBW. Drug use. Single mothers. Young mothers. Old mothers.

Independent of the impact of each of these causes, the fact that WHO and/or CIA and/or CDC doesn't expressly state that the numbers they use are not apples to apples numbers is irresponsible. Further, they don't even try to normalize for various factors that I mentioned above.

Dave Ribar said...


The CDC was explicit about the numbers it used; again, see Table 1 of its report.

Also, without a lot of detailed individual-level data, it's not possible to standardize across countries in the comprehensive way that you suggest.

The CDC did standardize along one dimension--gestational age--and found that that could account for much, though not all, of the difference between the U.S. and Sweeden.

Bubba said...

"The infant mortality rate is not a 'proxy' for the 'medical care delivery system.' Instead, it is an outcome from that system.

Spare us the rigid mindset, Dave.

You're misusing statistics in your usual stubborn way to support a political and social conclusion not merited when all the information is considered..

It's just a convenient way for you to prop up a point make that's intellectually not supportable.

It's also just standard Dave procedure at work here.

pino said...

Good afternoon Dave,

"The CDC was explicit about the numbers it used; again, see Table 1 of its report. "

As I have mentioned before, the source for Table 1 of the CDC data IS the Eurostat. I scraped this from the CDC document and can befound directly below Table 1.

SOURCE: NCHS/National Vital Statistics System for U.S. data and European Perinatal Health Report, p. 40 for European data:

"The CDC did standardize along one dimension--gestational age--and found that that could account for much, though not all, of the difference between the U.S. and Sweeden."

And yet none of the agencies reporting the data mention that ONE fact. That if we account for that one dimension, the US' ranking moves up substantially.

In short, all I am saying is that it is irresponsible to use this metric, as reported, to implicate a health care system.