During the Covid-19 pandemic, a measure known as “excess mortality” has been used to predict how many deaths were caused by the disease. The value of the measure is that, at least ostensibly, it factors out deaths from non-Covid causes, showing only those deaths caused by Covid-19. Historical demographic data is used to calculate expected mortality in a given year. Anything above the expected mortality is considered to be excess mortality caused by an unusual event – in this case the Covid-19 pandemic.
Here’s the catch – official, recorded Covid 19 death statistics do not line up with the numbers in the “excess mortality” calculation through the pandemic. There are fewer Covid-19 deaths reported and recorded than there are estimated in the excess mortality figures. According to the Centers for Disease Control and Prevention (CDC), the difference amounts to over 300,000 deaths “unaccounted for” in the excess mortality estimation since February 2020.
Many are questioning how these extra deaths can be explained. David Wallace-Wells, writing for the New York Times, calls these unaccounted for deaths the “excess excess” mortality.
Although many experts speculate on what is causing the excess-excess mortality, no clear answer has emerged. Possibilities include pandemic delays in seeking out care for other health conditions, indirect pandemic effects such as anxiety and depression from isolation, and longer term effects of Covid-19 (including what is referred to as “long Covid”).
However, none of these fully explain the phenomenon. The shape of the trajectory of excess-excess mortality closely tracks the trajectory of the official deaths from Covid 19. See the NYT’s charts here. This suggests the explanation is strongly linked to Covid-19, but has not been officially recorded as such. A likely (at least partial) explanation is that the excess-excess deaths were caused by Covid-19, but recorded as something else in official records. For example, when elderly deaths occurred at home, and deceased were pronounced dead without being tested for Covid 19.
The insurance industry is particularly interested in understanding the causes of these excess-excess deaths. For now, despite the many theories floating around, the real cause remains a puzzle.