Two Key Takeaways From The New CDC Life Expectancy Data

The headline of Wednesday’s New York Times report announces, “U.S. Life Expectancy Falls Again in ‘Historic’ Setback,” and the just-released data from the CDC is shocking: During the second year of the pandemic, life expectancy not only didn’t recover from its 2020 drop, but it dropped further, from 78.8 years in 2019 to 77 in 2020, down further to 76.1 years in 2021, based on provisional data.

What’s more, gaps among ethnic/racial groups (mostly) widened sharply.

To be sure, Hispanic and Asian-ethnicity Americans’ life expectancy remained higher than that of (non-Hispanic) white Americans, in line with general patterns in which immigrants have greater life expectancy than native born residents, though the gap for Hispanics narrowed, from 3.1 years’ greater life expectancy to only 1.3 years. (For Asian-ethnicity Americans, the gap widened slightly, from 6.8 to 7.1 years.)

However, for Black Americans, the 4 year lower life expectancy in 2019 became 5.6 years in 2021. And for American Indian/Alaskan Natives (AIAN, in CDC parlance), the drop was even worse, from a 7 year gap at 71.8 years to an 11.2 year gap at 65.2 years’ life expectancy.

To what extent, are these drops of life expectancy due to Covid-19, rather than other causes?

From 2019 to 2020, the CDC reports that 90% of the drop in Hispanic life expectancy was attributable to Covid; the corresponding rates were 68% for whites and 59% for blacks. (No breakdown was provided for the AIAN or Asian categories.) However, the CDC data splits its breakdowns into “contributions to decreases” and “contributions to increases” rather than overall net effect. Those readers who are used to looking at data and charts will expect a “waterfall” style chart; the CDC version is not this, and is not particularly helpful.

In any event, relative to the 2020 baseline, the further decreases in life expectancy during 2021 had multiple causes. Only among the White demographic group was Covid the cause of over half of the decline; unintentional injury (including overdoses) was the second-largest contributing factor and for the AIAN demographic group, worsening rates of death due to chronic liver disease and cirrhosis played almost as substantial a role.

And, finally, it is important to understand that the CDC data shows a continued improvement in life expectancy due to reductions in death due to such causes as influenza/pneumonia, COPD/emphysema, Alzheimer disease, diabetes, and perinatal conditions (infant deaths). In fact, strikingly, in 2021, heart disease was a contributor to increased life expectancy in the Black, Hispanic, and Asian demographic groups, but a contributor to decreased life expectancy for the White and AIAN groups.

Again, though, the way the CDC provides its information means that, when it comes down to it, there is much that is simply missing; we do not know the magnitude of the improvements in life expectancy due to these causes, just that it exists. It even seems likely, or at least possible, that some of the apparent improvement in mortality due to these factors was actually because deaths were actually recorded as Covid deaths instead (whether due to multiple causes of death or other reasons).

Having said all this, it is important to understand what “life expectancy” means in the first place. Yes, these rates dropped in 2020 and 2021 — but that does not mean that you, or I, have had our own personal life expectancy shortened.

The type of life expectancy calculation reported by the CDC is called “period life expectancy.” As life insurance actuary Mary Pat Campbell explains, period life expectancy takes “the mortality experience for the whole population during a specific time period, usually a single year (in this case, 2021), and then calculat[es] life expectancy as if the mortality seen by the full population during that year was the one a person would be seeing during a lifetime. No person actually lives through a mortality pattern like this, because we’re not in a ‘steady state’ for mortality.”

Do we expect the Covid death rates we saw in 2020 or 2021 to continue indefinitely? If not, then period life expectancy is not a helpful measure for planning for the future, and actuaries, demographers, and others turn to cohort life expectancy based on specific birth years, for example, how many more remaining years of life someone born in 1970 can be expected to have, on average.

Period life expectancy is not useless, of course; it’s a snapshot, and a simple yardstick for measuring the overall health and well-being of a country or a demographic group from one time period to the next. But as we saw in trying to unpack the specific causes of deaths that play into this, period life expectancy is too simple a figure to give us a real understanding of covid impacts or other trends.

Instead, as again, Mary Pat Campbell explains, what’s really much more useful to provide this broader understanding is the mortality rate, which can be unpacked by age group, to see the impact of Covid and other causes of death: for young adults, up through age 35, there was more excess (above-average) mortality due to drug overdoses during the pandemic years, than due to covid; for Gen Xers, as they go from their early 40s to their late 50s, covid shifts from the highest-ranking among multiple causes of excess mortality to the cause which far overshadows all others; and the dominance of Covid in the causes of excess mortality only increases for Boomers and the Silent generation, where Campbell explains discusses the life expectancy improvement factors in the CDC data:

“There are a few possibilities here, given the delta/omicron wave of 2021. First, we have the ‘they would have died of something anyway’ explanation — that explains why someone who would have died of heart disease died of COVID instead in 2021. Remember, total mortality for the age 85+ group was still higher in 2021 than in 2019. It’s just that a bunch of causes of death were also lower than usual, unlike what we saw with other adult age groups.

“But let’s think of that increase in Alzheimer’s deaths in 2020 — could be the nursing home deaths of 2020, could be due to neglect during lockdowns and other causes. This could be a ‘they died earlier, so they couldn’t die later’ explanation.”

Campbell’s data also provides visualizations of the degree to which mortality rate-improving factors had an effect — turns out the magnitude of these offsetting factors is actually very small, except for in the oldest-old.

Now, this sort of analysis of mortality data is far more enlightening than the data that the CDC provides, and it would be great to see Campbell’s graphs split out by racial/ethnic group to better understand that dramatic headline statistics reported by the Times and elsewhere, but, honestly, Campbell isn’t being paid by anyone to produce this data and it would be nice for the people who are being paid to produce something as helpful as her tables and charts.

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