It seems well-known that the health risks of COVID-19 are larger for the elderly. But how much larger? And what is the trajectory of risk across age? Andrew T. Levin, William P. Hanage, Nana Owusu-Boaitey, Kensington B. Cochran, Seamus P. Walsh, Gideon Meyerowitz-Katz provide a set of estimates "Assessing the Age Specificity of Infection Fatality Rates for COVID-19: Meta-Analysis & Public Policy Implications" (NBER Working paper 27597, as revised October 2020, also available via medRxiv, which is a "preprint server for the health sciences").
Also, Andrew Levin is the genial and informative talking head in a 15-minute video discussing the main approach and results.
As the title implies, the paper is an effort to pull together evidence on the health effects of COVID-19 by age from a variety of sources. Two figures in particular caught my eye. This figure shows the "infection fatality rate"--that is, the the ratio of fatalities to total infections. The different kinds of dots on the figure show results from different kinds of studies. The red line is their central estimate, which is surrounded with estimates of the uncertainty involved.
As the authors write: "Evidently, the SARS-CoV-2 virus poses a substantial mortality risk for middle-aged adults and even higher risks for elderly people: The IFR is very low for children and young adults but rises to 0·4% at age 55, 1·3% at age 65, 4·2% at age 75, 14% at age 85, and exceeds 25% for ages 90 and above."
The COVID-19 risk for the elderly is clearly substantial. But how does one think about the risk for those, say, in the 45-65 age bracket. Their COVID-19 risk is clearly lower than for the 85 year-olds. But how does their COVID-19 risk compare with other everyday risks? In his talk, Levin offers a comparison with risks of death from an automobile crash by age.