On Measuring Lethality of COVID-19

A simple, yet important, issue throughout the pandemic has been one of the lethality of COVID-19 cases. I will use a simple Case Fatality Rate (CFR) formula to show that the lethality of COVID-19 in the DC area is largely on-par with the national (i.e. United States) trend, with the DC area being better (i.e. lower) on the margins.

According to the CDC's "Principles of Epidemiology", CFR is "...the proportion of persons with a particular condition (cases) who die from that condition. It is a measure of the severity of the condition." The provided generic CFR formula is:

Number of cause-specific deaths among the incident cases divided by Total number of incident cases
× 10 n

















For this, I will use (on a day-by-day basis) COVID-19 fatalities (6,745) as the numerator, and COVID-19 cases (399,691) as the denominator:

6,745/399,691

Hence, as of 14 April 2021, CFR for the DC area was 1.6876%. By contrast the overall CFR for the United States was 1.80%. Even if we round the DC figure up to 1.69% for the purpose of consistency, that 0.11% difference accounts for 440 lives "saved" here in the DC area, compared to if the DC area had a CFR of 1.80%.

That said, the CFR for DC is still close enough to the national figure that I think we can consider it to be largely in-line with the national CFR, particularly in light of the CFR for other advanced countries (e.g. Japan at 1.85%, France at 1.94%, Canada at 2.16%, and Germany at 2.60%).














(From https://ourworldindata.org/mortality-risk-covid, using data from the JHU COVID-19 data project)

As far as long-term trends go, the DC area matched the US as a whole in that CFR peaked in May 2020 before effectively leveling-off in January 2021, although the peak DC-area peaked at 4.38%, with a national-level peak at 6.26% (curiously, within two days of each other...13 May for the DC area and 15 May for the US).





(From https://ourworldindata.org/mortality-risk-covid, using data from the JHU COVID-19 data project)


There are plenty of factors that I cannot investigate in my personal capacity, such as stratified demographics (e.g. age groups), the effect of evolving medical treatment, and also more recently, the effect of vaccines.

What is pretty clear is that the DC-area generally follows the national trend in CFR.

Comments

  1. ronbrownfanApril 15, 2021 at 5:10 PM

    Seems like a useful metric for comparison purposes. However, I don't understand the "10 to the n" factor is the formula. Is this because deaths are typically reported per thousand or million?

    ReplyDelete
    Replies
    1. TYApril 15, 2021 at 7:51 PM

      I believe that may be so. I will admit that I omitted that element of the function.

      Delete

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