Covid-19 is especially hard on the old and frail, with 79% of the deaths attributed to the disease in the US among those 65 and older and 94% among people with at least one “comorbidity” such as diabetes, dementia, obesity or hypertension.
This has led some people to argue that most of the country’s 200,000-plus deaths so far from the disease somehow shouldn’t count, which is ghoulish and awful. But I don’t think it’s ghoulish or awful to point out that a lot of the people dying from the coronavirus this year would have died from something else in the not-too-distant future, albeit likely in more pleasant circumstances than alone in a hospital room hooked up to a ventilator.
By “a lot” I do not mean most, and by “not-too-distant future” I do not mean next month. Going purely by the age distribution of US Covid-19 victims, one recent study estimated that on average they would otherwise have had an additional 11.7 years to live. Attempts to adjust for underlying medical conditions among the victims bring that number down somewhat but not radically; a study based on data from Italy found that doing this reduced the lost life expectancy by about a year. Meanwhile, a recent estimate of the loss of quality-adjusted life years, which fully count years of good health and discount those beset by infirmity, put the average for US Covid victims at about seven.
Still, these averages do imply that tens of thousands of Covid-19 victims in the US had pre-pandemic life expectancy of less than a year or two, meaning that in the epidemic’s wake we should expect to see the phenomenon that is known in mortality studies by the definitely ghoulish term “harvesting.” As in, after the Grim Reaper makes an especially big harvest of souls, he’ll have fewer to reap in the immediate aftermath.
“You would expect a decline in deaths following an epidemic, arising from the fact that epidemics, by targeting frail individuals, make the population suddenly more ‘robust’ on average, which can then lead to a deficit of deaths once the epidemic is over,” explained mortality-statistics expert Michel Guillot, a professor of sociology at the University of Pennsylvania and senior researcher at the French National Institute of Demographic Studies.
For a straightforward example of the phenomenon, Guillot pointed me not to an epidemic but to an August 2003 heat wave that killed an estimated 45,000 to 50,000 Europeans, the vast majority of them elderly. In its immediate aftermath, deaths among French people ages 85 and older reverted to more or less normal, with the aftereffects of heat stress perhaps canceling out any harvesting effect. But in 2004, they were below normal all year long, ending down 13.5% from the 2000-2002 average. Together, 2003 and 2004 saw a 6.6% drop in 85-and-older deaths from from the earlier period, probably attributable to mild winter flu seasons as well as harvesting effects. It was as if the heat wave had never happened (except that it had).
In other words, optimists hoping for a post-pandemic mortality decline that cancels out at least some of the death toll from Covid-19 aren’t necessarily wrong, but they may have to wait a while. This is especially true in the US, where the disease has never stopped spreading and weekly deaths from all causes have remained well above normal since late March. Because US weekly mortality data trickle in with long and variable lags from the individual states, and the people at the Centers for Disease Control and Prevention don’t do a great job of either communicating the incompleteness of the data or successfully adjusting for it in their excess-death estimates, some of the aforementioned optimists have repeatedly fooled themselves and others into believing that the Covid mortality wave is over and the happy time of reduced deaths is upon us, but so far they’ve invariably been proved wrong when the numbers get revised upward over subsequent weeks.
The CDC’s numbers for New York City do appear to be up-to-date, though, and as one of the places in the US hardest hit by Covid-19 in the spring and most successful in restraining it since, it also seems the likeliest to see below-normal mortality among the elderly. And yes, total deaths among those 85 and older have been a little lower than the 2017-2019 average since mid-June — but only 0.7% lower. From late March through early May, they were 324% higher.
Several European countries were even more successful in driving down Covid-19 cases and deaths over the summer than New York City was, although there’s been a lot of backsliding lately. So did deaths among the elderly fall below normal during the hiatus? They did, here and there. Among the countries I looked at, the effect was most apparent right after the epidemic waned in Italy, but it wasn’t very big and with data available only through midyear we don’t know yet if it lasted.
Bloomberg
