All-Cause Mortality Data for the USA

After much searching and asking friends if they can find the data, I’ve finally found a source for all-cause mortality data for the United States of America. It’s the CDC’s excess mortality data page. There is a ton of data on this page, and I recommend checking it out. Before I show you a screenshot of what it looks like at the moment, I’ll explain why this data is so useful.

Consider the following hypothetical: a person suffers from COPD (chronic obstructive pulmonary disorder). This is a deadly condition where the lungs are deteriorating, and it just keeps getting worse until the person dies from it. Suppose the person with COPD probably is sufficiently advanced that they only have six months to a year left, and then they get COVID-19, and die. Did they die from COVID-19 or from COPD? Different doctors, hospitals, and medical systems will answer that question differently, and all in good faith.

(To see how it can all be in good faith, how much the COVID-19 pushed them over the edge is something God knows, but man can’t know with certainty. Had they gotten something else, like the flu or a common cold, that might have pushed them over the edge instead. If they got a common cold and died, we would call it a COPD death, not a common cold death. This is just one example, there are a lot of cases which are legitimately judgement calls on which people disagree.)

This disagreement is especially a huge problem internationally. There’s absolutely no reason why doctors in Russia, China, Kenya, and Paraguay would have the same standards for things; it’s not like they would ever talk to each other, or report anything to the same place.

However.

Everyone diagnoses death in the same way, at least after a few minutes. Not being alive is a very difficult condition to miss, no matter what tests are common or what doctors are habituated to look for or what their beliefs or customs are on the primary cause of death. And what is true across countries is helpful across states, too. It doesn’t take much looking for find endless debate about whether COVID-19 deaths are being over- or under-counted; we can be fairly sure about deaths being accurately counted.

Or, rather, we can be after about eight weeks. One problem that we run into here is that the CDC has found that only about 60% of deaths are reported within 10 days of the death; it takes about 8 weeks to get completely stable numbers. This is a very long time to wait, so they have algorithms based on how long it typically takes each reporter that feeds into the CDC to report all deaths to predict, after 10 days, what the final count will be. It looks like lately they’ve been under-predicting deaths in the first week by (about) 15-20%, though it varies from week to week, and I don’t have enough data to say that with certainty. I’ve tracked it for 3 weeks now and the numbers seem to get reasonably stable (by which I mean changing by less than 5%) after a few weeks of being on the chart. That said, everything in the right-most 8 weeks does need to be taken as provisional, the further to the right, the more provisional, and bearing in mind that the provisional numbers have a bias towards under-predicting the final number of deaths per week:

As you can see, this spans a little more than 3 years. I’ve no idea what happened in January of 2018; I don’t recall any news items about excess mortality back then, nor anything that would have been an explanation for it.

I’m not, here, going to get into any sort of in-depth analysis. I think it’s a bit early for analysis, aside from a few observations. The first is that the excess deaths do, more or less, follow the same pattern as COVID-19 deaths reported by the CDC, which gives some confidence that those numbers on COVID-19 deaths aren’t wildly inaccurate.

The other observation is that COVID-19 is obviously not affecting mortality all that much. The worst weeks for excess mortality were about 40% excess deaths, but that only lasted a few weeks. Excess mortality quickly dropped to below 20% and often below 10%. Or you can just look at the area in blue under the yellow line versus the area in blue above it (that’s not quite perfect because there is a bit of uncertainty built into the yellow line, but not a lot). It did go back up again, in time with the second wave of COVID-19 cases, but it appears to have peaked. The peaking is within that 8 week window, but the CDC’s numbers on COVID-19 deaths show that they peaked back in august, so if all-cause follows COVID-19 deaths as well as it has in the past, it is likely that the peak in all-cause deaths we’re seeing is real. We’ll be able to be a lot more confident about that in November or December.

By the way, an interesting question, which we won’t be able to settle for months at the earliest, is whether there will be a discernible drop in all-cause mortality for a while. If there is, that would strongly suggest that COVID-19 mostly just hastened the deaths of people who were going to die soon anyway. It will be interesting to watch for this.

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.