The Covid-19 pandemic this year has often been described as the worst public health crisis in the US since the Spanish Flu of 1918. And there has certainly been nothing since then that compares. But early estimates indicate that the increase in deaths this year may have even been worse than during the worst year of the Spanish Flu.
Population has of course grown, so the relevant figures to compare over time are death rates – the share of the population that died each year. In addition, while it should not make much of a difference to the annual percentage changes, for longer-term trends one should look at the age-adjusted figures, which control for changes in the age structure of the population (as older people are more likely to die in any given year).
The National Center for Health Statistics, part of the CDC, provides such figures for the years 1900 to 2018. The CDC also has separate figures for deaths and population for recent years, up to 2019, and hence the crude (not age-adjusted) death rate can be calculated for 2018 and 2019. From this one can estimate what the percentage change in the death rate was for 2019, which should be close to the percentage change in the age-adjusted rate as the population age structure changes only slowly over time.
Finally, the estimate for what deaths in 2020 will be was obtained from a December 22 Associated Press article reporting on recent CDC figures. It reports that the US “is on track to see more than 3.2 million deaths this year”. And this may be a conservative estimate. It would imply an increase of 345,162 over the number of deaths in 2019. But as I write this, the number of deaths reported by Johns Hopkins from Covid-19 alone was 345,271. While a share of those who have died due to Covid-19 this year would have died later in the year from other causes, analyses of “excess deaths” have consistently found that the increase in deaths this year has been well in excess of the number that has been attributed specifically to Covid-19. For example, a CDC study in October estimated that for the period from late January (when Covid-19 was first recognized in the US) to October 3, there were 299,028 more who had died than one would have expected under normal conditions, while (over that period) only 198,081 deaths were directly attributed to Covid-19. That is, the increase in the number of deaths during the period (over what would have been expected had this been a normal year) was 51% higher than the number of recorded deaths due to Covid-19.
We will not have the final figures for 2020 for some time. But even accepting the conservative estimate of 3.2 million deaths in the US in 2020, the percentage increase in the number of deaths in the US per 100,000 of population was about the same as (and indeed very slightly higher than) in 1918, the year of the Spanish Flu. In both years, the increase in the death rate was close to 12%.
I was surprised that the increase in the death rate this year was anywhere close to what it was during the Spanish Flu. It is truly astounding. But it is especially surprising given that, as the AP article cites, the number of deaths of Americans in 1918 rose by 46%. How can that be consistent with the 12% increase in the death rates? There are several factors that account for this.
To start, the increase (using another CDC table) was from 981,239 deaths in 1917 to 1,430,079 in 1918, or an increase of 448,840 (or 45.7%). But note that a footnote to that CDC table indicates that these figures include military deaths in World War I. This differs from the practice in later years, where military deaths are excluded. World War I military deaths totalled 116,516 (according to official Department of Veterans Affairs figures), and almost all came in 2018. While some share of these were due to soldiers dying from the Spanish Flu, I do not have figures for what those might have been. Leaving that aside, the increase in non-military deaths in 1918 would have been close to 34%, and adjusting for US population growth in those years the increase in the death rate would have been 32%.
That is still significantly higher than the close to 12% increase in the death rate in the CDC figures. There are two reasons for this. First, note, as was discussed above, these CDC figures adjust for changes in the age structure of the US population over the century, and use population weights of the year 2000. The US age structure has shifted markedly since 1918, with a far higher share of the population now in the older age groups. Had the age structure in 1917 and 1918 been the same as it was in 2000, the base overall death rates in those years, excluding the impact of the Spanish Flu, would have been higher. Second, the Spanish Flu was especially lethal for those in the middle age groups – those in their 20s, 30s, and 40s. The young and the old were less affected. But those in the middle age groups account for a smaller share of the age structure using the weights of the year 2000 than they had in 1918. While I do not have the data to allow me to decompose the specific numbers, simple simulations with plausible parameters suggest that at the year 2000 population shares, the increase in the age-adjusted death rate of 12% can be consistent with the 32% increase observed in 1918 when military deaths are excluded, or the 46% overall increase when military deaths and population growth are included.
Few expected when Covid-19 was first detected in the US that the death rate this year would be anywhere close to what it was during the Spanish Flu. But it has been. Sadly, the crisis was severely exacerbated by the singularly incompetent management of the Trump administration. The Washington Post had a particularly good summary of the many things the Trump administration got wrong in addressing Covid-19 this year in a December 26 editorial. Or one can compare the US record to that of other countries. The US this year had 1,040 deaths due to Covid-19 per million of population. Canada had 412 per million, or 40% of the US rate. If the US had simply matched what its neighbor to the north was able to do, the US would have had 137,000 deaths instead of more than 345,000, or 208,000 fewer deaths. And others have done even far better. New Zealand has had only 5.0 deaths per million, and Taiwan just 0.3 per million.
Better management would have been possible. But the Trump administration failed, and hundreds of thousands of Americans have died. As the Post editorial noted:
“It was always going to be hard. But the worst did not have to happen. It happened because Mr. Trump failed to respect science, meet the virus head-on and be honest with the American people.”