The Covid-19 Death Rate Looks Less Bad in Historical Perspective

 (Part II of “Statistics and the Pandemic”)

My preceding blog post pointed out that excess mortality statistics show Covid-19 death rates to be much worse in most countries than are reported by official statistics.  In this sense, the pandemic is even worse than one thought.

But the news all around us is already depressing.  A consideration of longer-term history allows a more encouraging perspective on mortality — provided we handle the statistics properly.

A recent newspaper headline proclaimed that the 2020 jump in the US death rate (essentially excess deaths) not only was the worst in many decades but supposedly surpassed even the global influenza of 1918 (“Record Jump in the US Death Rate Last Year,” NYT, 4/25/2021): “The U.S. death rate in 2020 was the highest above normal since the early 1900s — even surpassing the calamity of the 1918 flu pandemic.”

It would seem surprising if, with all the advantages of modern medical science and greater economic resources, Americans fared worse in 2020 than in 1918.  The truth is, we didn’t.  It is true that the federal and state governments could have done far better.  But the outcome wasn’t worse than the so-called Spanish flu.  The New York Times article was misleading in describing the comparison of excess deaths between 1918 and 2020.   (The mortality rate in 2020 “increased 16 percent from 2019, even more than the 12 percent jump during the 1918 flu pandemic.”)

According to the CDC, “from 2019 to 2020, the estimated age-adjusted death rate increased from 715.2 to 828.7 deaths per 100,000 population.”  (Unadjusted for age, 3.4 million Americans died last year, out of a population of 330 million.)  That was an increase in mortality of 0.114 percentage points [from 0.715% to 0.829%].  To be sure, the rise in 2020 was tragically large, unmistakably reflecting the pandemic.   But why describe the result as an increase in the death rate of 16% [calculated as .114%/.715%]?

If one compares the 2020 crisis to the rise in the age-adjusted death rate from 2,278 per 100,000 in 1917 to 2,542 per 100,000 in 1918, an increase in mortality of 0.264 percentage points [from 2.278% to 2.542%], one learns that the earlier episode was more than twice as deadly.  It is misleading to describe the 1918 jump in US mortality as 12 % [calculated as 2.542%/2.278 %] and therefore less severe than the recent experience.

The point is that the 2020 hit only looks worse than the 1918 hit when compared to other causes of death, which have declined by much more over the last century.

What is most striking in a graph of the death rate in the US over time – even more striking than the exceptional leaps of 1918 and 2020 – is the otherwise gradual but strong downward trend in mortality from 1910 to the present.  Even the awful reversal of 2020, from 0.7% to 0.8%, still leaves the death rate below what it was as recently as in 2000.

Steven Pinker’s book Enlightenment Now is a good antidote for the impression to which we are all susceptible that the world is going to hell on most dimensions.  Despite everything, favorable long-term trends in fact show up in global statistics on infant mortality,  life expectancy, violent death, poverty, literacy, and more other criteria than one would have thought possible.

Such historical progress is not automatic and we should not take it for granted. Pandemics illustrate what can go wrong.  Faith in “science, reason, and humanism,” has made progress possible. So has holding leaders accountable. Good statistics help.