It's Still Not the Flu...
... and thinking it is positions us for defeat.
17 April 2020 | David Merrick
So it's April 17, and we stand at around 690,000 cases and 36,000 fatalities. The President has announced his guidelines for reopening the U.S., and the State of Texas has taken the lead and announced a plan to get back to normal(ish) in the coming months. Other states will follow, and soon.
America is chomping at the bit to get back to work, and with good reason. In the past four weeks, we've seen 22 million new unemployment claims. That's not only a record it is inconceivable and certainly not sustainable. The markets took a huge dive and show no hurry to recover. Oil prices are so low it feels like the 90's. To put it bluntly, our economy is in the crapper.
And only 36,000 fatalities! Why, that's lower than the flu! (Spoiler, that's sarcasm.) Except for a couple of things. First, in the first four months of 2018, there were 31,484 deaths from influenza and pneumonia in the United States . How about 2017, the same four month period? 24,871 deaths from influenza and pneumonia . So the fatalities in the last two months from COVID-19 is above (somewhat) both of those figures. So apples to apples, we are marginally worse off than just the flu. Oh, and remember 2009? The H1N1 Pandemic that many memes try compare this to, and how we don't remember it? In 2009, same four month period, 19,588 deaths. In 2010 it was 19,297. So... can we stop comparing?
Second... back to 2018. I know my memory is often poor - but I don't remember locking myself in my house for a month in 2018. Do you? No, you don't. So we got those 31.484 fatalities as we ran around and lived our lives normally. Social distancing will suppress the spread on influenza as well. In fact, I just saw (but cannot find again now) a stat that showed deaths last week from all causes were down to 27% of the expected values. So flu right now isn't nearly the issue is normally is - because of social distancing.
Third, it's become clear that too many Americans don't understand exponential growth. 2 Becomes 4, which becomes 8, then 16, and 32, and 64... 128, 256, 512, 1024... and it continues on and on. It's not linear (2+2+2+2+2...) An FSU professor of astrophysics put together a simple plot of the growth of cases and fatalities. It shows that yesterday we had 26,081 fatalities, but if we had not tried to mitigate the spread and had allowed it continue unchecked, we could be sitting at 185,651 fatalities.  Is the model perfect? No, it's a simple log-linear plot that demonstrates the math. However, it is valid enough.
The IHME models have gone to a three day update cycle... and they are getting completely vilified for being so... wrong. As of today, they estimate 60,308 fatalities in the U.S. through August.  A couple of weeks ago is well over 100,000. Three days ago it was 68,000. People don't understand models, just like they don't understand hurricane forecasts (which are also models). The IHME graphs show a range of uncertainty that goes from 34,063 deaths to 140,381. When the final number is outside that range, start talking to me about inaccuracies.
We also must remember - models are based on experience and good data. We have neither of those in this situation. The last major pandemic was 102 years ago. To say the data of that day is spotty is an understatement. We can't quantify infection rates and fatalities for that event beyond saying, 'it was real bad'. So without historical data, it's difficult to model things. Without accurate current data, it is impossible. The IHME and the Imperial College models were both based on the data coming out of China. It's now clear that this data was flawed (at best). Garbage in, garbage out.
As new data is gathered every day on COVID-19, that information is brought into the models. The result of this? Different results. Estimates fluctuate up and down - infuriating to the lay person, but expected. This is not an indicator of poor effort, but of refining what we know. Quick, tell me mathematically how effective locking me in my house is going to be on the spread of COVID-19! I can't. Some folks are trying, because that is the only way we will be able to understand how to beat this. That's how we make better predictions.
Does that mean the models were useless? No. Sure it was wrong, but it did what was necessary - it spurred us to action. It got us to stay inside (somewhat) and slow the spread. We "flattened the curve" and bought ourselves some time without seeing a hundred thousand deaths in a few weeks. 
So here we are, getting ready to move to the next phase. We don't have enough testing capacity (and we desperately need it) and we don't have a timeline on a vaccine. What we do have is a cracked economy and a need to get moving again. If we open up too fast, or too soon, that IHME model is going to get much more wrong - in the direction we don't want. We risk a second bloom - a resurgence.
We can move forward, but we need to understand how this is going to work. It's not 'over'. We are not out of the woods; SARS-CoV-2 is still out there, looking to spread. So what models exist for us? How about Sweden?
No, those articles you may have read saying that Sweden wasn't 'doing anything' aren't true. Implications that Sweden was trying to achieve herd immunity are also... not correct. Sweden has changed their habits, but they have done it without government edicts. They are trying to mitigate, and they *may* be getting it right.  Universities are shut down, as are high schools, but younger children are in school. Workers are telecommuting. Gatherings are limited to 50 people. Restaurants and bars are open, only for table service - no packing into a pub and drinking. Swedes are staying home, and they are sheltering their elderly and vulnerable. COVID-19 is still spreading in Sweden, but they are slowing things down.
If we look at Sweden now, we may see a model for our next few months. What strategies can we adopt here? We can get some aspects of our economy moving again without allowing COVID-19 unrestricted growth. But to do this, we need to change the culture here - we need to keep our distance, wash our hands, wear a mask, stay home when sick, eliminate crowds of more than 10... In other words, we can probably get retail and manufacturing going again. Open some schools. We can travel some. But we shouldn't be planning to attend any concerts or sporting events.  Most importantly, we have to be vigilant and flexible. If numbers start to climb, we need to slow down. It's also clear we'll need regional, state, and county plans and decisions. Not all areas are on the same timeline or have the same geography or population.
The numbers we see today are a win and a result of our national effort. They are not an indicator that we over reacted. Our numbers today do not mean the models were useless or dangerous or wrong. The numbers today mean that we have stuck together to preserve a lot of human life. Pat yourself on the back. And buckle up, because it's going to be a strange, bumpy ride until a vaccine arrives.
1. Centers for Disease Control and Prevention, National Center for Health Statistics. Underlying Cause of Death 1999-2018 on CDC WONDER Online Database, released in 2020. Data are from the Multiple Cause of Death Files, 1999-2018, as compiled from data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program. Accessed at http://wonder.cdc.gov/ucd-icd10.html on Apr 17, 2020 4:32:10 PM
5. They may be getting it wrong too... we'll know in a couple of months.
6. Not official recommendations.