I heard that US life expectancy fell again. Does this mean *my* lifespan will be shorter?

Sadly, life expectancy losses have been even more extreme for Black and Hispanic Americans (4.0 years and 4.2 years respectively) compared to White Americans (2.4 years).

“Life expectancy” is one measure we use to summarize mortality in a population. You’ve probably heard this statistic in the news your whole life—”life expectancy at birth for American males is 79 years,” for example.

But what does life expectancy mean? The number of years someone born today can expect to live….right?

Not quite. (Cue the Nerdy Demography Music ):

Life expectancy at birth is the number of years someone born today could expect to live… IF THEY WERE TO LIVE THROUGH THE AGE-SPECIFIC DEATH RATES OF *THIS* YEAR for their entire lives.

You read that right–life expectancy is calculated based on the pretend lives of an imaginary (or “synthetic”) group of people living through the risk of mortality at each age as measured today, without any improvements (or worsening). It’s like the average lifespan of someone born today *if* mortality risks were frozen in time. So it’s NOT a forecast for any real newborn.

Life expectancy is a snapshot of *current* mortality conditions each year. A long-term trend up is a good indication that many individuals are living longer than previous generations.

Large swings upwards or downwards can tell us something dramatic has changed, as it has with COVID-19. The size of these drops allows us to compare such mortality shocks across time and place—it’s one way we know that COVID mortality has been MUCH worse than even bad flu seasons in the past, and overall the worst mortality shock since World War II.

Since we will hopefully not have pandemic levels of mortality *every year* of someone’s life (PLEASE, FOR THE LOVE… NO!!!), these life expectancy life expectancy drops don’t mean that your own lifespan has necessarily been shortened.

The life expectancy losses capture those who have already died, so for individuals looking forward the real question is how COVID-19 will continue to affect on-going mortality risk in the future.

WHY is life expectancy a useful measure if it’s not actually how long I can expect to live?!

Life expectancy has some advantages over other measures such as excess mortality or raw mortality rates. The total number of deaths depends a lot on population size, as well how many young versus old people there are in a country. This makes it more difficult to compare across countries or over time.

We also might care more about deaths at younger ages when someone has more remaining years to live. Life expectancy accounts for all these issues, allowing direct comparisons across countries of different sizes and age structures, and for the same country over time. Deaths that happen at younger ages contribute more to losses in life expectancy than deaths that happen at older ages. This is why countries that reduce infant and child mortality see rapid gains in life expectancy.

So, while life expectancy isn’t a perfect measure, it IS super useful for comparing mortality across countries and time.

Which brings us back to the US…what’s going on there?

US loss expectancy losses during the COVID-19 pandemic have been much worse than all “peer” Western European countries.

Most of those countries had smaller losses in 2020 and saw “bounce backs” of life expectancy in 2021. Italy, for example lost more than one year of life expectancy in 2020 but regained 5 months of that loss in 2021. England & Wales lost 11.5 months of life expectancy in 2020, but gained 2.1 months of that back in 2021.

So, among wealthier countries, the US has done really poorly during COVID-19. Life expectancy losses in 2021 were actually *worse* than they were in 2020, despite the vaccine roll-out and improved knowledge of the virus.

What can explain the higher mortality in the US? There is no one clear answer, and researchers will be untangling the reasons for many years to come.

One notable difference in the US has been the ages of those dying of COVID-19. While many European countries saw COVID mortality very concentrated at older ages, the US saw more deaths below age 65. This was true in 2020 and the deaths shifted even younger in 2021 after the vaccine roll-out. This younger age profile of COVID-19 deaths hits life expectancy harder and could reflect worse underlying health and/or higher exposure risk for those of working ages in the US.

Life expectancy has been lagging European countries for many years now, so some of this US disadvantage may reflect vulnerabilities in underlying health that were exacerbated by the COVID-19 pandemic.

Vaccine and booster take-up is lower in the US compared to many European countries, which may account for the different experiences especially in 2021 when many more people were infected thanks to the Delta and Omicron variants.

While most of the life expectancy losses can be attributed to confirmed COVID deaths, the US also saw continued increases in deaths due to drug overdoses in the past two years.

BOTTOM LINE:

Large life expectancy drops in the US reflect the huge mortality toll of the COVID-19 pandemic.

Life expectancy losses this large have not been seen since World War II.

While these numbers should raise alarm bells about the health of our population overall, they don’t predict your own lifespan.

The best strategy for minimizing the long-term impact of COVID-19 on your health and longevity is to:

1) Stay up to date on your vaccines and boosters

2) Continue precautions to avoid frequent infections (we know it seems hard to completely avoid infections these days, but it’s still better to have *fewer* infections in your remaining lifetime).

Stay safe, Stay well…Stay Nerdy.