mortality

Excess Mortality and Vaccination Rates in Europe

Jeremy HorpedahlLeave a comment

Much ink has been spilled making cross-country comparisons since the start of the COVID-19 pandemic. I have made a few of these, such as a comparison of GDP declines and COVID death rates among about three dozen countries in late 2021. I also made a similar comparison of G-7 countries in early 2022. But all such comparisons are tricky to interpret if we want to know why these differences exist between countries, which surely ultimately we would like to know. I tried to stress in those blog posts that I was just trying to visualize the effects, not make any claims about causation.

Here’s one more chart which I think is a very useful visualization, and it may give us some hint at causation. The following scatterplot shows COVID vaccination rates and excess mortality for a selection of European countries (more detail below on these measures and the countries selected):

The selection of countries is based on data availability. For vaccination rates, I chose to use the rate for ages 60-69 at the end of 2021. Ages 60-69 is somewhat arbitrary, but I wanted a rate for an elderly age group that was somewhat widely available. There is no standard source for an international organization that published these age-specific vaccine rates (that I’m aware of), but Our World in Data has done an excellent job of compiling comparable data that is available.

Note: I’m using the data on at least one dose of the vaccine. OWID also has it available by full vaccine series, and by booster, but first dose seemed like a reasonable approach to me. Also, I could have used different age groups, such as 70-79 or 80+, but once you get to those age groups the data gets weird because you have a lot of countries over 100%, probably due to both challenging denominator calculations and just general challenges with collecting data on vaccination rates. By using 60-69, only one country in my sample (Portugal) is over 100%, and I just code them as 100%. Using the end of 2021, rather than the most current data, is a bit arbitrary too, but I wanted to capture how well early vaccination efforts went, though ultimately it probably wouldn’t have mattered much.

Also: dropping the outliers of Bulgaria and Romania doesn’t change things much. The second-degree best fit polynomial still has an R2 over 0.60 (for those unfamiliar with these statistics, that means about 60% of the variation is “explained” in a correlational sense).

The excess mortality measure I use comes from the following chart. In fact, this entire post is inspired by the fact that this chart and others similar to it have been shared frequently on social media.

The chart comes from a Tweet thread by Paul Collyer. The whole thread is worth reading, but this chart is the key and summary of the thread. What he has done is shown the average and range of a variety of ways of calculating excess mortality. Read his thread for all the details, but the basic issues are what baseline to use (2015-2019 or 2017-2019? A case can be made for both), how to do the age-standardized mortality, and other issues. I won’t make a claim as to which method is best, but averaging across them seems like a fine approach to me.

For the y-axis in my chart, I just used the average for each country from Collyer’s chart. There are 34 countries in his chart, but in the OWID age-specific vaccination rates, only 22 countries were available the overlapped with his group. Unfortunately, this means we drop major countries like Italy, Spain, the UK, and Germany, but you work with the data you have.

For many sharing this and similar chart (such as charts with just one of those methods), the surprising (or not surprising) result to them is that Sweden comes out with almost the lowest excess mortality rate. Some approaches even put Sweden as the very lowest. Sweden!

Why is Sweden so important? Sweden has been probably the most debated country (especially by people not living in the country in question) in the COVID pandemic conversation. In short, Sweden took a less restrictive (some might say much less restrictive) approach to the pandemic. This debate was probably the most fevered in mid-to-late 2020, when some were even claiming that the pandemic was over in Sweden (it wasn’t). The extent to which Sweden took a radically different approach is somewhat overstated, especially in relation to other Nordic countries. And as is clear in both charts above, the Nordic countries all did relatively very well on excess mortality.

The bottom line from my first chart is that what really matters for a country’s overall excess mortality during the pandemic is how well they vaccinated their population. There seems to be a lot of interest on social media to rehash the debates about whether lockdowns (and lighter restrictions) or masks worked in 2020. But what really mattered was 2021, and vaccines were key. A scatterplot isn’t the last word on this (we should control for lots of other things), but it does suggest that a big part of the picture is vaccines (you can see this in scatterplots of US states too). It’s frustrating that many of those wanting to rehash the 2020 debates to “prove” masks don’t work, or whatever, either ignore vaccines or have bought into varying degrees of anti-vaccination theories. It’s completely possible that lockdowns don’t pass a cost/benefit test, but that vaccines also work very well (this has always been my position).

Why did Sweden have such great relative performance on excess mortality? Vaccines are almost certainly the most important factor among many that matter to a much smaller degree.

What About the US?

Note: for those wondering about the US, we don’t have the vaccination rate for ages 60-69 that I can find. Collyer also didn’t include the US in his analysis, it was only Europe. So, for both reasons, I didn’t include them in this post. The CDC does report first-dose vaccinations for ages 65+ in the US, though they top-code states at 95%. As of the end of 2021, here are the states that were below 95%: Mississippi, Louisiana, Tennessee, West Virginia, Indiana, Ohio, Wyoming, Georgia, Arkansas, Idaho, Alabama, Montana, Alaska, Missouri, Texas, Michigan, and Kentucky. These states generally have very high age-adjusted COVID death rates. Ideally we would use age-adjusted excess mortality for US states, but in the US that is horribly confounded by the rise in overdoses, homicides, car accidents, and other causes that are independent of vaccination rates (though they may be related to 2020 COVID policies — this is still a matter of huge debate).

On Counting and Overcounting Deaths

Jeremy Horpedahl2 Comments

How many people died in the US from heart diseases in 2019? The answer is harder than it might seem to pin down. Using a broad definition, such as “major cardiovascular diseases,” and including any deaths where this was listed on the death certificate, the number for 2019 is an astonishing 1.56 million deaths, according to the CDC. That number is astonishing because there were 2.85 million deaths in total in the US, so over half of deaths involved the heart or circulatory system, at least in some way that was important enough for a doctor to list it on the death certificate.

However, if you Google “heart disease deaths US 2019,” you get only 659,041 deaths. The source? Once again, the CDC! So, what’s going on here? To get to the smaller number, the CDC narrows the definition in two ways. First, instead of all “major cardiovascular diseases,” they limit it to diseases that are specifically about the heart. For example, cerebrovascular deaths (deaths involving blood flow in the brain) are not including in the lower CDC total. This first limitation gets us down to 1.28 million.

But the bigger reduction is when they limit the count to the underlying cause of death, “the disease or injury that initiated the train of morbid events leading directly to death, or the circumstances of the accident or violence which produced the fatal injury,” as opposed to other contributing causes. That’s how we cut the total in half from 1.28 million to 659,041 deaths.

We could further limit this to “Atherosclerotic heart disease,” a subset of heart disease deaths, but the largest single cause of deaths in the coding system that the CDC uses. There were 163,502 deaths of this kind in 2019, if you use the underlying cause of death only. But if we expand it to any listing of this disease on the death certificate, it doubles to 321,812 deaths. And now three categories of death are slightly larger in this “multiple cause of death” query, including a catch-all “Cardiac arrest, unspecified” category with 352,010 deaths in 2019.

So, what’s the right number? What’s the point of all this discussion? Here’s my question to you: did you ever hear of a debate about whether we were “overcounting” heart disease deaths in 2019? I don’t think I’ve ever heard of it. Probably there were occasional debates among the experts in this area, but never among the general public.

COVID-19 is different. The allegation of “overcounting” COVID deaths began almost right away in 2020, with prominent people claiming that the numbers being reported are basically useless because, for example, a fatal motorcycle death was briefly included in COVID death totals in Florida (people are still using this example!).

A more serious critique of COVID death counting was in a recent op-ed in the Washington Post. The argument here is serious and sober, and not trying to push a particular viewpoint as far as I can tell (contrast this with people pushing the motorcycle death story). Yet still the op-ed is almost totally lacking in data, especially on COVID deaths (there is some data on COVID hospitalizations).

But most of the data she is asking for in the op-ed is readily available. While we don’t have death totals for all individuals that tested positive for COVID-19 at some point, we do have the following data available on a weekly basis. First, we have the “surveillance data” on deaths that was released by states and aggregated by the CDC. These were “the numbers” that you probably saw constantly discussed, sometimes daily, in the media during the height of the pandemic waves. The second and third sources of COVID death data are similar to the heart disease data I discussed above, from the CDC WONDER database, separated by whether COVID was the underlying cause or whether it was one among several contributing causes (whether it was underlying or not).

Those three measures of COVID deaths are displayed in this chart:

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What’s Killing Men Ages 18-39?

Jeremy Horpedahl3 Comments

The all-cause mortality rate in 2021 for men in the US ages 18-39 was about 40% higher than the average of 2018 and 2019. That’s a huge increase, especially for a group that is not in the high-risk category for COVID-19. What’s causing it?

Some have suggested that heart disease deaths, perhaps induced by the COVID vaccines, is the cause. This is not just a fringe internet theory by anonymous Twitter accounts. The Surgeon General of Florida has said this is true.

What do the data say? The first thing we can look at is heart disease deaths for men ages 18-39.

The data I’m using is from the CDC WONDER database. This database aggregates data from US states, using a standardized system of reporting deaths. The most important thing to know is that in this database, each death can one have one underlying cause, and this is indicated on the death certificate. Deaths can also have multiple contributing causes (and most deaths do), and the database allows you to search for those too. But for this analysis, I’m only looking at the underlying cause.

Here’s the heart disease death data for men ages 18-39, presented two different ways. First the trailing 12-month average. Don’t focus too much on that dip at the end, since the most recent data is incomplete. Instead, notice three things. First, there was a clear increase in heart disease deaths. Second, that rise began in mid-2020, well before the introduction of vaccines. Third, once vaccines started being administered to this age group in Spring 2021, the number of deaths leveled off (though it didn’t return to pre-pandemic levels).

Here’s another way of looking at the data: 12-month time periods, rather than a trailing average. I created 12-month time periods starting in March and ending in February of the following year. I’ve also truncated the y-axis to show more detail, not to trick you. But don’t be tricked! The deaths are up 2-3%, not a more than doubling as the chart appears to show.

We can see in the chart above that the rise in heart disease deaths for young males completely preceded the vaccination period. Something changed, for sure, but the change wasn’t the introduction of vaccines. Heart disease deaths (by underlying cause) are only up 2-3%, while overall deaths are up around 40%.

So, to repeat the title question, what is killing these young men?

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GDP Growth and Excess Mortality in the G7

Jeremy Horpedahl1 Comment

Two weeks ago my post looked at GDP growth during the pandemic. But of course, economic growth isn’t the only important outcome to look at in the pandemic. Health outcomes are important too, and indeed I have posted about those in the past alongside GDP data.

Today, my chart looks at the G7 countries (representing roughly half of global wealth and GDP), showing both their economic performance (as measured by real GDP growth) and health performance (as measured by excess mortality through February 2022).

The US has clearly had the best economic performance. But the US also had the highest level of excess deaths per capita (not all of this is from COVID — US drug overdoses are also way up — but even using official COVID deaths, the US still tops this group).

Japan had the best health performance, in fact amazingly no cumulative excess deaths through February 2022 (this has risen very slightly since then, but I stopped in February so all countries had complete data). However, Japan also had slightly negative economic growth.

Which country ends up looking the best? Canada! Very low levels of excess deaths, and at least some positive economic growth. Not as much growth as the US, but Canada is the second best performer in the G7.

To give some context of just how low the level of deaths have been in Canada, first recognize that the US had 1.1 million excess deaths in the pandemic through February 2022. If instead our excess deaths had been roughly equal to Canada on a per capita basis, we would have only had 180,000 excess deaths in the US, saving over 900,000 lives.

Some of Canada’s COVID policy have been overly restrictive, such as the vaccine mandates that sparked protests in February 2022. But by then, Canada had already largely achieved it’s COVID victory over the US and most other G7 nations. Compare excess mortality in Canada with the US: the only big wave in Canada that came close to the US was the Spring 2020 wave. After that, Canada was always much lower.

Violence, Guns, and Policy in the United States

Jeremy Horpedahl10 Comments

The United States is a uniquely violent country among high-income democracies. And by the best available data on homicides, the US has always been more violent. Homicides are useful to look at because we generally have the best data on these (murders are the most likely crime to be reported) and it’s the most serious of all violent crimes.

Just how much more violent is the US than other high-income democracies? As measured by the homicide rate, about 6-7 times as violent. We can see this first by comparing the US to several European countries (and a few groupings of similar countries).

Let me make a few things clear about this chart. First, this is data for homicides, which are typically defined as interpersonal violence. Thus, it excludes deaths on the battlefield, genocides, acts of terrorism (generally speaking), and other deaths of this nature. That’s how it is defined. If we plotted a chart of battlefield deaths, it would look quite different, but there’s not much good reason to combine these different forms of violent death.

On the specifics of the chart, prior to 1990 these data are averages from multiple observations over multi-year timespans (generally 25 or 50 years). The data on European countries comes from a paper by Eisner on long-term crime trends (Table 1). The countries chosen are from this paper, as are the years chosen. Remember that historical data is always imperfect, but these are some of the best estimates available. For the US, I used Figure 5 from this paper by Tcherni-Buzzeo, and did my best to make the timeframes comparable to the Eisner data. The data are not perfect, but I think they are about as close as we can get to long-run comparisons. For the data from 1990 forward, I use the IHME Global Burden of Disease study, and the death rates from interpersonal violence (to match Eisner, I average across grouped countries).

When we average across all the European countries in the first chart and compare the US to Europe, we can see that the US has always been more violent, though the 20th century onwards does seem to show even more violence in the US relative to Europe. (These charts are slightly different from some that I posted on Twitter recently, especially the pre-1990 data as I tried to more carefully use the same periods for the averages — still only take this a rough guide).

And what is the main form by which this violence is carried out? In the US, it is undeniably clear: firearms. Between 1999 and 2020, there were almost 400,000 homicides in the US (using CDC data). Over 275,000 of these, or about 70%, were carried out with firearms. The next largest category is murder with a knife or other sharp object, with about 10% of murders. And homicides have become even more gun-focused in recent years: about 80% of murders in 2020-21 were committed with guns.

So, there’s the data. But the important social scientific question is: Can we do anything about it? Are there any public policies, either about guns or other things, that will reduce gun violence? Could restrictions on gun use actually increase homicides, since no doubt guns are also used defensively?

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COVID Deaths, Excess Deaths, and the Non-Elderly (Revisited)

Jeremy Horpedahl8 Comments

While we know that COVID primarily affects the elderly, the mortality and other effects on the non-elderly aren’t trivial. I have explored this in several past posts, such as this November 2021 post on Americans in their 30s and 40s. But now we have more complete (though not fully complete) mortality data for 2021, so it’s worth revisiting the question of COVID and the non-elderly again.

For this post, I will primarily focus on the 12-month period from November 2020 through October 2021. While data is available past October 2021 on mortality for most causes, data classified by “intent” (suicides, homicides, traffic accidents, and importantly drug overdoses) is only fully current in the CDC WONDER data through October 2021. This timeframe also conveniently encompasses both the Winter 2020/21 wave and the Delta wave of COVID (though not yet the Omicron wave, which was quite deadly).

First, let’s look at excess mortality using standard age groups. For this calculation, I use the period November 2018 through October 2019 as the baseline. The chart shows the increase in all-cause deaths in percentage terms. It is also adjusted for population growth, though for most age groups this was +/- 1% (the 65+ group was 3% larger than 2 years prior).

A few things jump out here. First notice the massive increase in mortality for the 35-44 age group (much more on this later). Almost 50% more deaths! To put that in raw numbers, deaths increased from about 82,000 to 122,000 for the 35-44 age group, and population growth was only about 1%. And while that is the largest increase, there were huge increases for every age group that includes adults.

Also notice that the 65+ age group certainly saw an increase, but it is the smallest increase among adults! Of course, in raw numbers the 65+ age group had the most excess deaths: about 450,000 of the 680,000 excess deaths during this time period. But since the elderly die at such high rates in every year, the increase was as large in percentage terms.

One related fact that doesn’t show up in the chart: while there were about 680,000 excess deaths during this time frame in the US in total, there were only about 480,000 deaths where COVID-19 was listed as the underlying cause of death. That means we have about 200,000 additional deaths in this 12-month time period to account for, or a 24% increase (population growth overall was only 0.4%).

That’s a lot of other, non-COVID deaths! What were those deaths? Let’s dig into the data.

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Are the COVID Vaccines Effective at Preventing Death?

Jeremy Horpedahl3 Comments

A recent analysis by the Kaiser Family Foundation of CDC data suggests that about 234,000 COVID deaths in the US could have been prevented if everyone was vaccinated. That’s about 25% of all COVID deaths throughout the pandemic, and about 60% of COVID deaths since June 2021 (roughly the time when most older adults in most states had had a chance to be vaccinated).

The first way to think of that death rate is tragic, given that so many lives could have been saved. Rather than being the high-income nation with the highest COVID death rate, the US could have been more in line with countries like Italy, the UK, and France. The US actually had a lower COVID death rate than Italy and the UK when the vaccine roll-out began, and today we could be at about France’s level with better vaccination rates.

But there’s a flipside to the KFF numbers. If 60% of COVID deaths since June 2021 were preventable, that means 40% weren’t preventable. Furthermore, the same data show that about 40% of COVID deaths in January and February 2022 were fully vaccinated or had boosters. That sounds like the vaccines might not work very well! So what does this all mean? Let’s dig into the data from the CDC a little bit.

The first, and most important thing, to recognize is that most American adults are vaccinated (about 78%), so unless vaccines are 100% effective (and they aren’t, despite some public officials overenthusiastic pronouncements early in the vaccine rollout), there are still going to be a lot of COVID deaths among the vaccinated. If 100% of the population was vaccinated, 100% of the deaths would be among the vaccinated. The key question is whether vaccines lower the chance of death.

And they do. Let’s see why.

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What’s a Sewer Worth?

Jeremy HorpedahlLeave a comment

Have access to clean water and a functioning sewer system is something that many Americans take for granted. Not all Americans, of course, especially those in rural areas not connected to an urban water system. But most Americans do. But how much is it worth?

It’s a hard question to answer. We know clean water and sewers probably have large effects on disease transmission. For example, Ferrie and Troesken (2008) looked at several major improvements in Chicago’s water system, and found that there were large declines in mortality from diseases like typhoid fever after the improvements (here’s an ungated working paper, with the much better title “Death and the City“). But the limits of earlier studies like this are that they primarily looking at a time series of mortality rate and relating this to some change in public infrastructure. A good attempt, but perhaps not convincing to everyone.

A better method would be to look at not mortality rates but property values. People are, surely, willing to pay more for a home with piped water and a sewer system. But how much more? Knowing this could give us better information on the value of the water systems. And that’s exactly what the authors of a new working paper do, once again visiting Chicago in the nineteenth century to look at how much property values increased after the installation of water and sewer systems. The paper is “The Value of Piped Water and Sewers” by Coury, Kitagewa, Shertzer, and Turner (ungated version).

The effects are huge. There most conservative estimate is that sewer and water systems doubled property values (a 110% increase), but the effect could be much larger (almost 4 times as much, if I am reading it correctly, under other reasonable assumptions).

People are willing to pay a lot for sanitation, it turns out.

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Are Car Accidents Getting Labeled as “COVID Deaths”?

Jeremy HorpedahlLeave a comment

Of all the increases in mortality in 2020, one that is notable is motor vehicle accidents. There were 43,045 deaths from motor vehicle accidents, according to the final CDC data. This means motor vehicle accident was listed on the death certificate, even if it was not determined to be the “underlying cause,” though for 98% of these deaths the accident was listed as the underlying cause.

The increase from past years was large. Compared with 2019, there were over 3,000 more motor vehicle deaths, though such as increase is not unheard of: 2015 and 2016 each saw increases of around 2,500. Even so, the crude death rate from motor vehicle accidents in 2020 was the highest it has been since 2008.

If that weren’t bad enough, another theory emerged in 2020 and continues to be suggested today: that car crashes are being labeled as “COVID deaths,” artificially inflating the COVID death count. While one can find this claim made almost daily by anonymous Twitter users, one of the most prominent statements was on Fox News in December 2020. Host Raymond Arroyo said that car accidents were being counted as COVID deaths, and that due to errors like this COVID deaths could be inflated by as much as 40 percent. Senator Marco Rubio made a similar claim on Twitter in December 2021, though he was talking about hospitalizations, not deaths.

Back in 2020, many doctors and medical professionals tried to debunk the “car accidents being labeled as COVID deaths” claim, but the problem was we didn’t have complete data. Anonymous anecdotes were cited, but medical professionals tried to reassure the public this wasn’t the case or at least wasn’t widespread.

But now, we have the data! That is, the complete CDC mortality data for 2020 available through the CDC WONDER database.

What does this data show us? Short answer: there aren’t that many car accidents being labeled as COVID deaths. At most, it’s about 0.03% of COVID deaths.

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800,000 Deaths? Or 1 Million Deaths?

Jeremy Horpedahl5 Comments

According to the Johns Hopkins COVID tracker, the US has now surpassed 800,000 COVID deaths during the pandemic. The CDC COVID tracker is almost to 800,000 too. But is this number right? Confusion about COVID deaths and total deaths has been rampant throughout the pandemic, especially when comparing across countries.

One method that many have suggested is excess deaths, which is generally defined as the number of deaths in a country above-and-beyond what we would expect given pre-pandemic mortality levels. It’s a very rough attempt at creating a counterfactual of what mortality would have looked like without the pandemic. Of course, you can never know for sure what the counterfactual would look like. Would overdoses in the US have increased anyway? Hard to say, though they had been on the rise for years even before the pandemic.

So don’t treat excess deaths as a true counterfactual, but just a very rough estimate. I wrote about excess deaths in the US way back in January 2021 (feels like a lifetime ago!), and at the time for 2020 it looked like the US had about 3 million total deaths (in the first 48 weeks of 2020), which was about 357,000 deaths more than expected (again, based on historical levels of the past few years), or about 13.6% above normal.

But once we had complete data for 2020, deaths were even higher: about 19% above expected, or somewhere around 500,000 excess deaths. This compares with the official COVID death count of about 385,000 in 2020 for the US.

What happens if we update those numbers with the most recent available mortality data for 2021? Keep in mind that data reporting is always delayed, so I’ll just use data through October 2021. The following chart shows both confirmed COVID deaths and total excess mortality, cumulative since the beginning of 2020.

As we can see in the chart, there are a lot more excess deaths than confirmed COVID deaths. There were already over 1 million excess deaths through the end of October 2021 in the US, cumulative since January 2020. This compares with about 766,000 confirmed COVID deaths. That’s a big gap!

We could spend a lot of time trying to understand this gap of 250,000 deaths. Is this under-reporting of COVID deaths? Is it deaths caused by government restrictions? Is it caused by the overwhelming of the health system?

I won’t be able to answer any of those questions today. Instead, let’s ask a different question: is the potential US undercount of COVID deaths unusual?

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