Corona by numbers

COVID-19, the rule of six, R₀ & 2 metre distances?!? It’s easy to be bamboozled by numbers when trying to understand what is going on right now, we’ll do our best to help.

30th May 2020

As we enter the third month of the lockdown with nothing to do each evening but watch the news, information overload is becoming a real problem. With so much data and statistics flying around, all changing so rapidly, it’s difficult to know what is going on.

We aren’t epidemiologists or virologists, so can’t give any meaningful help, except to stay home and follow the advice of the experts.

But what we would like to consider ourselves experts in is data visualisation.

So, we’ve searched the web for some of the most interesting COVID-19 statistics we can find and given the graphics the Patently treatment, hopefully making them a bit easier to digest.

How does COVID-19 compare to other diseases?

Current estimates of COVID-19’s case fatality rate — a measure of the proportion of infected people who eventually die — suggest that the coronavirus is less deadly than the pathogens behind other large-scale outbreaks, such as of Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS) and Ebola.

But the infection also seems to spread more easily than other diseases, including seasonal influenza. Calculations of the virus’s basic reproduction number, or R₀ — the number of people on average one infected person will pass the virus to — suggest a range of 2–2.5.

Like the case fatality rate, R₀ is an estimate that can vary considerably by location and age group etc; over time it is likely to be revised. It is calculated using models that take into account how long an infected person remains contagious, the likelihood of them infecting contacts and how often they come into contact with other people.

When displaying four metrics at once we need to get creative with the visualisation. Here we have minimum R₀, maximum R₀, fatality rate and disease name, all to combine into something intelligible. By colour coding the disease names we can remove tags from the main graph area and leave the key details unobstructed.

Original data by Nature (

Which European countries have the pandemic under control?

Analysing the moving average across Europe (for countries with more than 2,500 cases and more than 50 deaths) we can see where numbers of cases are rising and falling.

It’s been a hard slog, but with -3.8% change in reported cases over the past seven days, the UK appears to have turned a corner — let’s hope we can keep the spread contained.

Radial line graphs can seem alien at first, but with so many countries to be represented, a traditional bar chart would spread out so far that the comparisons would be lost. When your eyes adjust to the semi-circular axis, the information becomes clear.

Original chart by Tom Evans / Data from Johns Hopkins University

How does COVID-19 effect the sexes?

Simple but powerful statistic this one, men are nearly twice as likely to die of COVID-19 than women.

We could’ve used a pie chart of bar graph, but occasionally and infographic is spot on. Here, the male icon is 70% larger in area than the female icon, instantly conveying the relevant information.

Original data: UK Office of National Statistics

How do existing medical conditions increase the risk?

The Italian Portal for Epidemiology for Public Health studied 355 deaths from COVID-19 and evaluated the victims’ medical records recording any existing medical conditions. They concluded the people with multiple underlying health concerns are 74x more likely to die than someone with none at all.

Waffle charts are perfect for this sort of data. Displaying percentages graphically when one or more values are very low (i.e. below 2%) can be tricky. Many of you will not have seen one before, but they are simple enough to be understood right away.

Original data: Italian Portal for Epidemiology for Public Health

How serious are the symptoms?

A study of 44,672 confirmed cases in mainland China determined that the majority of infections are ‘mild’ and hospitalisation is not necessary.

Sometimes fancy charts are useful, and others the simplest is the perfect option, here we think a basic pie chart highlights the facts most clearly.

Original data: China Centre for Disease Control & Prevention

Which age groups are most at risk?

Across the UK, the over 60’s are currently the most at risk, accounting for over 90% of total cases, with 80–89 year olds the age group in the most jeopardy.

Again, a simple chart, but it is all that is needed.

Original data: UK Office on National Statistics

Have you seen any COVID-19 data represented in a new and interesting way? Let us know via social media.



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