Coronavirus: Are we underestimating the death toll, globally?

The Covid-19 epidemic is a fight with an invisible enemy. What’s also worrying is that we just don’t know how bad the disease really is.
Many people wonder whether we’re overestimating its deadliness, since countries find it impossible to test those with few or no symptoms. The case fatality rate is the ratio of coronavirus deaths to the number of infected patients. If we underestimate the latter, the detected fatality rate will look much higher than the real one. That’s why there’s such huge interest in scientific models that suggest the overall infection rate is far in excess of the official numbers. If that were true, the mortality rate across the population would fall to less worrying levels.
However, Italy’s experience shows that countries may also be underestimating the other side of the ratio: the death toll. As hospitals become overcrowded, patients are being asked to stay at home until they display the most serious symptoms. Many will die in their houses or nursing homes and may not even be counted as Covid-19 cases unless they’re tested post-mortem.
Last week, two researchers from northern Italy made this point forcefully when looking at Nembro, a small town near Bergamo that has been very severely hit by the outbreak. Writing in Italian newspaper Corriere della Sera they found there had been 158 deaths in the town in 2020 so far, as opposed to 35 on average in the previous five years. They noted that Nembro had only counted 31 deaths from Covid-19, which looks like an underestimate.
In other towns nearby, including Bergamo itself, the trend seemed identical. The researchers made the point that the only reliable indicator in the end will be “excess deaths” — namely, how many more people have died in total compared to a “normal” year.
The statistical advantage of “excess deaths” is that they give you a fuller picture of the human cost of the pandemic. The number of people who die of Covid-19 is a significant part, but not all of it. There will also be people who suffer from other illnesses and who aren’t treated properly because hospitals are overcrowded, intensive care units full and ambulances take longer to arrive. Conversely, there will also be fewer deaths from, say, road accidents, because of the draconian restrictions some countries have chosen to impose. All of this will be captured in this one indicator. If Italy is any guide, other countries should not underestimate the human toll of Covid-19.

—Bloomberg

Ferdinando Giugliano writes columns on European economics for Bloomberg
Opinion. He is also an economics columnist for La Repubblica and was a member of the editorial board of the Financial Times