Health and Infant Mortality

In an earlier article I used infant mortality and longevity as 2 indicators of healthiness of a population. Recently there has been some discussion over the infant mortality rate aspect of this measure. So I thought I’d revisit the infant mortality statistic. As you will shortly see it seems I reached a correct conclusion for the (slightly) wrong reasons.

Wrong reason #1. It’s hard to directly compare other countries.

One claim is that other countries measure infant births differently from the US and indeed from each other. Some commentators claim that an infant birth isn’t counted until the baby is at least a week old. If this were true then the US would clearly have more infant deaths in the first week of life than these other countries (and by comparison these other countries should have a somewhat higher still-born rate). But I have found no country that measures births by this mechanism, these commentators are either making this “fact” up or are referring to 3rd world countries and so were never included in my original article. But the general point does appear to be valid. For example what counts as a still-born baby is not quite uniform from country to country. The US measures a baby as born alive if it shows any signs of life after birth where some other countries count a baby as still born if it is under-weight or too small or born too prematurely. Granted, this is not as extreme as waiting a week to declare a successful live birth, but this would clearly result in the US recording more infant deaths in the first day after birth than other countries.

Fortunately the World Health Organization keeps records of when infants die, within the first 24 hours, within the first 7 days, within the first month and within the first year. So if this factor is a significant contributor to the high US infant mortality one quick way to adjust for this is to exclude those infants who died on first day. The chart below shows this and two things are apparent (if you look closely).

IM-by-type

  1. The US moves closer to the rest of the pack when first-day deaths are excluded from the statistics. So it appears the US system of measuring live births is at least a partial contributing factor to the relatively high US infant mortality rate.
  2. But even taking this fact into consideration, the US infant mortality rate is higher than the other industrialized countries. Granted, the gap between the US and the next highest country isn’t as large as it was before we adjusted for this effect, but the change merely allowed the US go from “last place by a lot” to “last place by a little”.

Wrong reason #2. All countries in the developed world may be “good enough”.

The simple fact is that all of the industrialized countries have very low infant mortality by historical standards. Less than 10 out of 1000 babies die within their first year of life in these countries. While the countries with higher infant mortality (in the 100 out of 1000 range) may also have poorer medical care in general, it could be the case that in the low mortality rate countries, improving general medical care may not further improve infant mortality.

Think of it this way. In a country where the general population enjoys excellent health infants may die prematurely for reasons that affect only infants, something like SIDS for example. Improvements in clean water, access to doctors, and healthy food will provide benefits to adults and infants, but will not significantly affect deaths due to SIDS. So for countries where the infant mortality rate is 10 or less it *may* be the case that improvements beyond this point are not good indicators of improving health of the general population.

But while this is plausible, for the past 5 years (2001 to 2005), many of the industrialized countries have seen their infant mortality rate consistently fall. So improvements are apparently on-going and may also have an effect on the general population.

5-year-IM

Infant mortality rate may still be a good indicator of general healthiness of a population, but there may be a better measure for “high healthiness” countries.

Why this doesn’t affect my conclusion.

The overall thrust of the earlier article was that for the dollars the US is spending on health care we ought to have spectacularly positive results. Results were categorized using both longevity and infant mortality. The US is last in longevity for the industrialized countries, but based on this article, it is reasonable to say the US is tied for first in infant mortality along with all the other industrialized countries. But this doesn’t change things much because a spectacular effort (extremely high health care costs per person) should result in a spectacular result (longevity/infant-mortality) and it doesn’t.

However, for something as complex as “quality of the medical system” I’m reluctant to rely on a single metric. It’s been suggested that the cancer survival rate may be a good measure to use and it’s also been suggested that this may show the US more favorably. A future article may replace the infant mortality rate with the cancer survival rate. Stay Tuned.

Notes

Ann Coulter has claimed this on various TV talk shows, but I could not find an online link

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