A little number sense can provide perspective on the COVID-19 risks

Model of the COVID-19 virus

Given the growing deluge of horrifying stories and images surrounding the global COVID-19 pandemic over the past few weeks, it is easy to find yourself reacting in one of two ways, both of which are potentially dangerous and neither of which is justified by the data.

First, when faced with daily reports of increasing numbers of deaths, you might think the odds are so stacked against you, there is little point in taking the recommended steps to protect yourself from infection. Alternatively, you could find yourself paralyzed with anxiety, afraid to do anything, and sink into a nihilistic depression.

Neither is justified by the actual data. In fact, what the data indicate are:

  • The odds are in favor of you avoiding infection if you follow the recommended preventative measures (avoiding contact with or close proximity to others, regular washing of hands, not touching your face, and a few others);
  • Even if you are infected, the odds favor you not having to be hospitalized;
  • The odds on you dying from COVID-19 infection are very low.

But just how good are those odds really? More specifically, how do they stack up against the risks associated with other things we encounter and do in life?

To allay my own initial anxiety, I did a few quick calculations, based on the data available in the press, and found that, while the risk of death is certainly much higher than that of, say, dying in an airplane crash, you are much more likely to die of heart disease than from the novel coronavirus.

How much more likely? Numerically, the risk is a whopping 28 times higher. But be careful. Whenever you see risk comparisons like that, you need to pay attention to what is being compared with what. On their own, the numbers tell you nothing; absent a proper context, that factor of 28 is meaningless.

In fact, that caveat about context can be significant whenever numbers are quoted; it is particularly so when a number is given to compare risks.

In the case of COVID-19, I went into the details of my calculation in a post in my personal blog profkeithdevlin.org. I leave you to follow the link and read what I said there. The mathematics is not hard; indeed, it is just basic arithmetic, along the lines of some of the more recent preceding posts in the SUMOP blog. The important thing is to keep in mind what the numbers refer to. The ultimate goal is not to produce a number — an answer; rather, it is to understand the relative risks.