What accounts for the “excess” excess deaths in the USA over the past three years?

Here’s a very interesting piece by David Wallace-Wells about an issue that I’ve been following closely over the course of the Covid pandemic. What accounts for all of the hundreds of thousands of excess deaths — about 300,000 by the CDC’s most recent calculations — that have occurred in America above and beyond the roughly one million excess deaths that can statistically be attributed to Covid? (A flaw in Wallace-Wells’s otherwise very lucid description is that he fails to note that not all Covid deaths are per se excess deaths, statistically speaking. In other words, if someone dies from Covid but would have died for some other reason over the course of the pandemic, even absent the pandemic and its primary and secondary mortality effects, that doesn’t count as an excess death. The CDC estimates that roughly one million of the 1.1 million official Covid deaths can be classified as excess deaths in terms of all-cause mortality statistics).

There are several hypotheses for all these “excess” excess deaths:

The first is delayed care — that the pandemic made people postpone treatment for various problems, as doctors and hospitals triaged resources, sending them toward those ill with Covid-19 and away from other issues, and canceled visits and screenings prevented new diagnoses (and therefore treatment).

A second hypothesis is about the indirect effects of pandemic restrictions: not just missed medical care but social isolation, anxiety and unemployment, which can worsen a wide range of conditions, as well as, potentially, suicide and homicide and even car accidents and overdoses, to the extent they each deviated from historical patterns.

A third hypothesis is that Covid-19 infection does harm to the body that can linger after recovery for some people — not just in what is conventionally called long Covid, but also in other ways, by disturbing the function of various organ systems. (Damage to the cardiovascular system has been one particular area of research focus.) “We still don’t really grasp the entire spectrum and breadth of disease yet,” the Yale immunobiologist Akiko Iwasaki told me. “We are still learning.”

Over the last year, papers exploring another theory — involving the risks of these “post-acute sequelae” with reinfection, not just initial infection — have also raised a considerable amount of alarm. Nearly every one of the many experts I spoke to about these papers emphasized their shortcomings, most notably that its authors were looking only at health outcomes among those people who had gone to see a doctor, feeling ill. The effect size was, if real, almost surely much lower than the write-ups suggest, they told me. But nearly every expert also was careful to say that, all things being equal, a reinfection was indeed bad for you, that especially if you were not in great health you’d want to avoid them and that in particular cases a reinfection could certainly contribute to the death of a patient from causes other than classic Covid pneumonia.

Another hypothesis is that Covid infection damages immune function in some patients in a long-lasting way. Here, too, there have been papers published tracing immunological effects, though there has also been a lot of contestation and pushback against — and contextualizing for — narratives of significant and widespread immunological dysfunction.

I’ve laid out each of these hypotheses separately, but of course, they are not disentangled. 

All these are superficially plausible, and probably play at least some marginal role, but I think DWW is correct when he concludes that there’s a much simpler and more straightforward explanation, that can explain the vast majority of the gap between official Covid excess mortality and overall excess mortality during the pandemic. The biggest clue in favor of this alternative hypotheses is that the waves of “excess” excess deaths themselves tend to so closely track the waves of official Covid deaths, which is not something we would expect to see if the various explanations given above were actually important causal factors.

[Jeremy] Faust believes he has at least part of an answer to the puzzle: that the excess excess mortality is, to a large extent, made up of deaths from Covid-19 that occurred at home and were not properly recorded or registered as a result.

The story he tells goes like this: A grandmother or grandfather is found nonresponsive at home; an ambulance is called; the paramedics declare the person dead; the grandparent wasn’t tested for Covid recently but had been feeling bad for a few days, according to the relatives, who themselves recently had Covid; the deceased also had heart disease, and so that is registered as the cause of death. In a hospital setting, in theory, doctors might add Covid to a death certificate in more cases than is justified, since all patients will have been tested and, because of in-hospital transmission, many will be positive. But in an at-home setting, you can’t attribute a death to Covid-19 without a positive test, which means there may be a significant share of those deaths going undiagnosed.

Throughout the pandemic, about 20 percent of in-hospital deaths have been attributed to Covid-19, compared to barely 2 percent of deaths at home. If you roughly triple the share of at-home deaths attributed to Covid — still well short of the share in hospitals — you make the Covid death toll a bit larger but almost entirely eliminate the excess excess gap. And if you adjust it to match the share of deaths attributed to Covid everywhere but homes — hospitals, outpatient clinics, nursing homes — you actually overshoot the gap.

This suggests strongly that somewhere in the neighborhood of 80 to 90 percent of the “excess” excess deaths in America over the past three years were simply Covid deaths that weren’t coded as such. (An excellent USA TODAY story goes into great detail to explain some of the reasons why that might happen).

That in turn leads to the conclusion that the Covid death toll in American since February of 2020 is more on the order of 1.4 million, rather than the official 1.1 million tally.

The official tally is still growing by about 3,500 Americans per week, but of course everyone is completely fed up with this topic by now, which is why nobody is getting vaccinated, and why the White House is for reasons driven by political calculation rather than medical science ending the federal government’s Covid emergency declaration in May.

Oh well.