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Politics : Formerly About Advanced Micro Devices -- Ignore unavailable to you. Want to Upgrade?

To: sylvester80 who wrote (1354840)	4/19/2022 5:21:20 PM
From: Broken_Clock	2 Recommendations Recommended By locogringo Winfastorlose Read Replies (1) \| Respond to of 1572942

statmodeling.stat.columbia.edu Is it really true that “the U.S. death rate in 2020 was the highest above normal since the early 1900s—even surpassing the calamity of the 1918 flu pandemic”? Posted on April 25, 2021 6:04 PM by Andrew tl;dr. No, it’s not true. The death rate increased by 15% from 2019 to 2020, but it jumped by 40% from 1917 to 1918. But, if so, why would anyone claim differently? Therein lies a tale. A commenter pointed to a news article with the above graphs and the following claim: The U.S. death rate in 2020 was the highest above normal since the early 1900s — even surpassing the calamity of the 1918 flu pandemic. . . . In the first half of the 20th century, deaths were mainly dominated by infectious diseases. As medical advancements increased life expectancy, death rates also started to smooth out in the 1950s, and the mortality rate in recent decades — driven largely by chronic diseases — had continued to decline. In 2020, however, the United States saw the largest single-year surge in the death rate since federal statistics became available. The rate increased 16 percent from 2019, even more than the 12 percent jump during the 1918 flu pandemic. Our commenter wrote: If one takes the “normal” death rate to be that of the year prior to a pandemic and one assumes that the total population doesn’t change all that much from one year to the next, then this sub-headline seems to be seriously incorrect. If one eyeballs the “Total deaths in the U.S. over time” chart in the article and then compares the jumps due to the 1918 pandemic and the 2020 pandemic, it seems pretty clear that the percentage increase in the number of deaths (and thus the death rate, assuming a roughly constant population) from 1917 to 1918 is much greater than the percentage increase from 2019 to 2020. The jump from 1917 to 1918 looks to be around 40% while the jump from 2019 to 2020 looks to be around 15% (based on measurements of a screenshot of the graph using Photoshop’s ruler tool). I was curious so I took a look. The above graphs include a time series of deaths per 100,000 and a time series of total deaths. (As an aside, I don’t know why they give deaths per 100,000, which is a scale that we have little intuition on. It seems to me that a death rate of 2.6% is more interpretable than a death rate of 2600 per 100,000.) Here’s what they have for 1917 and 1918 (I’m reading roughly off the graphs here): 1917: 2300 deaths per 100,000 and a total of 1 million deaths 1918: 2600 deaths per 100,000 and a total of 1.4 million deaths. This is an increase of 13% in the rate but an increase of 40% in the total. But I looked up U.S. population and it seems to have been roughly constant between 1917 and 1918, so these above numbers can’t all be correct! According to wikipedia, the U.S. population was 103 million in 1917 and 1918. 1 million deaths divided by 103 million people is 1%, not 2.3%. So I’m not quite sure what is meant by “death rate” in that article. The problem also arises in other years. For example, the article says that 3.4 million Americans died in 2020. Our population is 330 million, so, again, that’s a death rate of about 1%. But the 2020 death rate in their “Death rate in the U.S. over time” chart is less than 1%. I’m guessing that their death rate graph is some sort of age-adjusted death rate . . . ummmm, yeah, ok, I see it at the bottom of the page: Death rates are age-adjusted by the C.D.C. using the 2000 standard population. Compared to 1918, the 2000 population has a lot of old people. So the age-adjusted death rate overweights the olds (compared to 1918) and slightly underweights the olds (compared to 2020). The big picture here is that it makes 1918 look not so bad because the 1918 flu was killing lots of young people. Also, one other thing. The note at the bottom of the article says, “Expected rates for each year are calculated using a simple linear regression based on rates from the previous five years.” One reason why 1918 is not more “above normal” than it is, is that there happens to be an existing upward trend during the five years preceding 1918, so the implicit model would predict a further increase even in the absence of the flu. I’m not quite sure how to think about that. Anyway, the answer to the question in the title of this post is No. Age adjustment can be tricky! P.S. This is just a statistical mistake, but I wonder if there’s a political component too. There seems to be a debate about whether coronavirus is a big deal or not, epidemiologically speaking. I think coronavirus is a big deal: an increase of 15% in the death rate is a lot! But for some people, that’s not enough; it has to be the biggest deal of all time, or at least bigger than the 1918 flu. Hence you get this sort of headline. I have no reason to think this is deliberate political manipulation; rather, it’s just that when people make a mistake that yields a result that aligns with their preconceptions, they don’t always notice. Or maybe I just made a mistake and I’m misunderstanding everything here. Could be; it’s happened to me before. P.P.S. More here from Paul Campos, who points out the large drop in deaths from 1918 to 1919. It doesn’t seem implausible that whatever distancing and careful behavior was done in 1918-1919 in response to the flue had the effect of reducing infectious disease the following year. But this isn’t something I’ve thought a lot about; I guess there could be other explanations too.