(Note: Data updated as of March 31, 2020)

Objective of this article:

• To show where Canada and the US are right now, relative to other areas of the world
• To highlight what we can do to slow the curve

In my previous article I showed how we can line up different regions to see if we’re doing better or worse than expected. This article is going to expand on the previous one, including some adjustment for the different population sizes of different regions. Please note that you don’t have to read the previous article for this to make sense.

Sneak peak of the findings:

• Confirmed cases per million population is quite simply number of confirmed cases divided by the population, multiplied by one million. 1 case per million is just like it sounds “one in a million”. Hubei is at about 1,000 coronavirus cases per million. Canada is at just over 100 confirmed coronavirus cases per million, and the US is at about 250 cases per million.
• Canada is literally at the crossroads right now. As a country we can still follow the growth curve from South Korea and keep this situation manageable. But we could just as likely fall down the pathway of Spain, Italy and Hubei.
• The US was late to the party but they are catching up quickly! The US needs to step things up drastically if they want to bend their curve.
• The only thing that makes a difference now is that each one of us does what we can to reduce the number of new cases today. If every day we can reduce the spread of the disease to a smaller number than the day before, then we’re winning the war. It’s a simple as that.

Chart 1: Confirmed cases per million since the day of the 100th confirmed case

Confirmed cases

Many of us have seen the following chart of rapidly growing confirmed cases.

Chart 2: Confirmed cases since the date of the 100th confirmed case

It tells us that the US is in a worrisome pattern of rapid growth, mostly driven from the New York and New Jersey numbers. This chart also tells us that Canada is still in a relatively low number of confirmed cases.

The key shape we are looking for is the point of inflection on the S curve. This is the day when there are fewer new confirmed cases than in the previous day. The main places where we can see this curve is in those regions in China that have been through this for five or more weeks.

Chart 3: The S Curve

When we look at Italy, Spain and the US we can see that we’re still in the exponentially increasing side of the curve, we just don’t know if we’re close to the inflection point or not.

If there’s one thing you probably remember about anything “exponential” it’s that it’s hard to really see the first part of the curve. The y-axis scale can be changed to a logarithmic scale to make it easier to read.

Chart 4: Confirmed cases since the 100th confirmed case, using a logarithmic scale

This helps us see how things are changing over time. We can see from this perspective how similar all of the countries are in the beginning. We can see how the Hubei region started reducing their rate of growth in their third week after the 100th confirmed case, but that the US is actually accelerating in their third week. Looking at South Korea it is clear that they were able to reduce their growth rate in their second week and substantially slow the growth afterwards. The Canada curve is lower than these “worst case scenario” regions but it won’t be if Canada doesn’t hit the inflection point soon.

Taking into account the size of each region

Each of these regions have substantially different populations, so to put things in perspective we divide the number of confirmed cases by the population of each region. To make it so that we don’t have to read small decimal numbers it’s calculated as cases per one million population. So, if a country has 100 cases and a population of 100 million then they would be at 1 case per million.

Chart 5: Cases per million since the 100th confirmed case, using a logarithmic scale

The chart shows that Canada should be worried at this point, as it’s in the zone of Spain, Italy, and Hubei. Canada just passed the South Korea curve in the most recent few days. The US on the other hand has a very large population and as a result they have been under the curve. This would not be true if we were looking at New York and New Jersey specifically. The US is catching up with the pack rapidly and is on the trajectory to overtake Italy and Spain in another week.

The war is won and lost in the local regions

Even though this is a global pandemic it’s important to think locally. In Canada there are a number of provinces with very small numbers of confirmed cases, which makes the country look better than it might actually be.

Chart 6: Cases per million since the 100th confirmed case, Canadian provinces

As shown, when we look at the cases per million for Quebec things look much worse than what is happening in Spain. British Columbia, Alberta and Ontario were also looking worse but we can see that their growth curves are not as steep as the curve for Spain. The point here is that each local region needs to do what they can to minimize their local growth curves.

In a future analysis I’ll be looking at the impact of different approaches to testing. Again, each region is dealing with it differently. For example Quebec started using their own labs instead of the national lab to maximize speed of results for large volumes, and that was driving the big jump towards the end of week one. In contrast British Columbia continues to do very targeted testing.

Make every day count

Every single day we see the number of new confirmed cases reported through our local media channels. What matters most is that every single day we do everything in our power to make tomorrow’s number lower than today’s number. How we do that is:

• Don’t be lax about the guidelines … if you don’t really have to go out then don’t go out. If it’s 6 feet of separation then keep it to 6 feet or more. Don’t sing “happy birthday” just once when washing your hands … do it twice!
• Many people are bending the above rules a bit because they are convinced that they don’t have the coronavirus. To play it safe, assume that you’re one of the 30% who have it and don’t have symptoms.
• If you’re sick then treat yourself like you are patient zero in a global pandemic … you have one job to do your part: don’t pass it on to anyone else. That’s the biggest way you can help. Read and re-read the very helpful best practices guides and don’t overreact: https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/steps-when-sick.html

As of March 31, 2020 there are 168 countries that have data in the public dataset that also have reported at least 100 confirmed cases. The following charts show some examples of how different regions have been doing over the past few days.

Chart 7: New confirmed cases per day in Quebec

Quebec was doing great for a while … with the numbers decreasing more and more every day. Their numbers unfortunately bounced back up on March 27th and have generally increased since then. Of the 168 regions that are reporting who have more than 100 confirmed cases, there only 22 regions that are showing signs of improvement like the first four days in the above chart.

Chart 8: New confirmed cases per day in Canada

Canada was much more up and down in the pattern but the past couple of days have shown significant growth in new confirmed cases per day. About 82 or so regions in the data have an “unstable” pattern.

Chart 9: New confirmed cases per day in the US

The new confirmed cases per day in the US continue to show a generally increasing pattern. The overall situation in the US is dire, and they need to do something drastic to slow their curve. Unfortunately there are over 40 other regions in the world that are following this worsening pattern.

Main take away messages

In summary, these are the things that I did not know until I did this analysis:

• In general things are getting worse, with most reporting countries showing signs of “up and down” patterns of new cases per day, or increasing numbers of new confirmed cases per day.
• Canada can still turn this around, but only if we hit our inflection point in the next few days.
• The US will have to do something substantial, and do it quickly or this will far outpace what we’ve seen in Italy and Spain.
• What matters most is that we all do whatever we can to make the number of new confirmed cases for our own region lower tomorrow than they were today. This is now a community-based disease, which means that it’s all up to us at this point.

Data sources:

Much of the data that we need is publicly available on github. The following link includes daily data of confirmed cases for each country in the past several weeks:

https://github.com/datasets/covid-19/blob/master/data/time-series-19-covid-combined.csv

Please keep in mind that each day it shows the numbers that were reported across the world as of the previous day.