October 20, 2021
Data Viz: Covid Deaths in the US By Age Group, Over Time

As of this writing, October 20, 2021, total US Covid deaths are half what they were at their all-time high.

CDC Chart

But, Covid deaths among younger age groups, in the US, are at all-time highs.

CDC Chart

This begs for more insight.

First, I did a streamgraph. This shows change in proportionality of the age groups, as well as change in total, over time.

The streamgraph works. But, the changing total makes it hard to read the changes in proportionality. So, next, I visualized the data as an animated pie chart. You can control the animation, with the slider.

This shows the changing proportionality, better. But, you have to watch the animation, and it’s hard to follow all of the changes. It would be nice to read the changing proportionality in a static chart.

If you imagine inflating the streamgraph to fill the vertical space, you get a normalized stacked area chart. This removes visualization of the changing total, and fills the space with the changing proportionality. This gives us the clearest picture of the changing distribution of deaths among age groups.

What the data shows

Younger people have been increasing their share of COVID-19 deaths, in the US. The timing of this shift correlates with two obvious factors. The first factor is the rollout of vaccine availability, starting in December of 2020, for the most at-risk, and becoming widely available in April and May. The second factor is the spread of the Delta variant, which became dominant in the US in July of 2021.

Are younger people less likely to get vaccinated? Is Delta more harmful to young people? How can we answer those questions with more data viz?


D3.js was used for my charts, here. D3 is amazing because it lets you do anything. It was designed to provide developers with the fundamental tools that allow them to creatively build anything.

These charts are made on the platform, ObservableHQ.com, which provides the ability for charts to be embedded in pages in a way that is responsive, dynamic and interactive.

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