The Numbers Don’t Lie: Projecting the Impact of COVID-19Reading time: 5 minutes
The sudden prevalence of COVID-19 and its impact on our daily lives is an alarming development. Seemingly overnight, the way we do business and live our lives has radically changed.
For the past several weeks, I’ve been tracking the accuracy of a predictive model I built to forecast the rise of confirmed cases of COVID-19 in the United States. The model has been frighteningly accurate. I watched as it tracked with confirmed cases, starting with a couple of hundred and quickly climbing into the thousands. As you’ll see further down in the post, if we don’t take significant preventative steps immediately, the confirmed cases will very rapidly reach into the millions.
The impact of an exponentially increasing number of cases means that our healthcare system will soon hit its breaking point. There is already a severe shortage of basic supplies, like masks, gowns, and other protective gear, for healthcare workers. With no other options, nurses and doctors are reusing these supplies, increasing the likelihood of transmission at hospitals. If the spread continues at the projected rate, there won’t be enough space in ICUs and medical centers to handle the number of patients that will flood them for care.
I’m not writing this to cause panic, but the numbers are alarming. Some of us have not yet realized the importance of following suggested guidelines for social distancing. And for those who are following the guidelines, it sometimes feels like an overreaction. I’m here to assure you that taking these steps is NOT an overreaction. It’s is an absolutely critical step in preventing a catastrophic event.
The numbers don’t lie.
Here is a chart of confirmed case counts in the United States through March 19th:
The curve is steep, and it looks scary. Between March 3rd and March 19th, the number of confirmed cases increased from 118 to 13,667. As of today, March 20th, at 2:30 pm ET, we are now at 16,018 confirmed cases.
But that’s nothing. Below is a projection of what the trend could look like through the middle of April. It assumes a daily growth rate in confirmed cases of 30%. This is conservative, as the actual average daily growth rate since March 1st is closer to 33%. And the growth rate in the past 24 hours was significantly higher than that.
What this means is that without taking significant steps, we’re looking at nearly 3.5 million confirmed cases by the 9th of April.
What we can do about this?
The most important immediate step that we can all take is to practice social distancing and self-quarantining. Simply put, this buys us time to ensure our capacity to test and treat patients is where it needs to be to handle the spike.
By taking these measures, we are slowing the rate of spread of the virus. In the short term, this allows time for medical supplies and infrastructure to be put in place. Just as importantly though, this will spread out the number of infected patients going to hospitals and clinics over a longer period of time. Without social distancing and self-quarantining, there will be a flood of patients entering hospitals all at once. This will overburden the system in a very short period of time.
What about testing?
One important consideration here is that the United States currently has a lack of testing capacity. As of this week, the United States has only run 85,000 total tests. To put that in perspective, the US population is 330 million. In comparison, South Korea has already run more than 210,000 tests, and their population is around 51 million people. They have tested 1 out of every 240 of their citizens. The US has only tested 1 out of every 4,000 citizens.
The more people that can be tested, the easier it will be to slow the spread of the virus. There are many more actual cases of COVID-19 than we know of, because the lack of testing availability means healthcare providers have to be very selective about who they test.
This causes two problems: first, because the number of confirmed cases is artificially low, the public, despite being alarmed about the situation, is not as alarmed as it should be. This leads some people to see the guidelines around social distancing and self-quarantine as an overreaction. The truth is that, if anything, we’re under-reacting to the severity of the problem.
Secondly, there are thousands of COVID-19-positive people unknowingly spreading it to others right now. Since the virus’s symptoms are often mild, we have many people who are infected and have no idea. These people are going about their lives, infecting other people along the way. Every person who picks up the virus from an infected person will continue to spread the infection to more people, which has a compounding effect. The problem is growing worse and worse, and in many cases, goes completely undetected.
The more people we test, the better we’ll be at alerting the public, identifying the problem, and isolating infectious people.
A Comparison: COVID-19 Testing in the United States and South Korea
To emphasize the impact of testing, let’s compare our rate of transmission with that of South Korea, which did a remarkable job at testing and containing COVID-19’s spread.
The chart below shows the daily number of confirmed cases in both countries. In the US (the orange curve), the number of cases is increasing at an accelerating rate. South Korea hit an inflection point in the first week of March. Their number of cases is increasing, but at a slower rate than before. On March 19th, the United States surpassed South Korea’s case count. This chart is scary: it shows that South Korea has the virus under control, while the United States does not.
Again – the numbers don’t lie. Testing is critical to leveling the curve and controlling the spread of the virus. Without testing, we won’t be able to prevent transmission, treat those who are ill, or get things under control.
Social distancing and self-quarantine can feel like extreme steps. However, they are absolutely necessary to prevent the kind of impact forecast by the predictive model above. If, in several weeks, we’re able to go back to daily life and it doesn’t feel like anything significant happened, that’s a best case scenario. It doesn’t mean we overreacted – it means that social distancing measures had their intended effect. The goal here is to make the prediction incorrect by staying home and avoiding further spread of the virus as much as possible.
Additionally, it’s critical to make your state and federal representatives aware of how important testing is to controlling the spread of the virus. It’s through our representatives that we can take these critical steps, and together we need to make it a priority – because the numbers don’t lie, and if we don’t take action, we will see serious consequences.