NYC should brace for impact and shut down now

19 March 2020

Originally posted on medium.com

Five days ago I wrote this medium post (COVID-19: New York Will Be The Next Italy, But Doesn’t Have to Be). In it, I forecast that NYC’s hospitals would be at capacity as early as March 30. Unfortunately, I was wrong. New numbers suggest that NYC’s hospitals will reach capacity of approx. 3,000 cases by March 24. (This error was from a lower than anticipated case detection rate.)

While there is now nothing we can do to prevent reaching capacity short of immediately adding beds, we can prevent additional deaths and hospitalizations by fully shutting down NYC except for absolutely essential services, like Italy’s current restrictions.

Here’s the math behind this new projection.

  • COVID-19 Hospitalizations in NYC as of Mar 19 (today): 777 cases

  • COVID-19 Hospitalization rate from medical research: approx. 10%

  • Time from infection to hospitalization for severe COVID-19 cases: 7–9 days

Using this, we can estimate the number of infections 8 days ago.

  • 777 cases / 10% = 7,770 cases on Mar 11.

On Mar 11, the NYC region had 220 cases reported. Meaning:

  • Detection rate: 2.8% (220 reported cases / 7,770 estimated cases)

While testing capacity has increased substantially, it has barely closed ground with forecasted new infections, which have continued to grow exponentially. (We estimate a current detection rate of just 5.6%)

Since roughly 10% of cases require hospitalization, we can also forecast the total number of hospitalizations of coronavirus cases in the NYC region. We just take 10% of the cases in the forecast and shift them forward by 8 days, to account for the delay from infection to the onset of symptoms.

At the outset of this crisis, NYC had between 1,200 and 3,000 beds available for coronavirus cases. Since we already have 777, we will hit capacity no later than March 24. Unfortunately all of those cases are already infected over the last few days.

The question now is whether we will stop adding to the cases a week from today, after the hospitals are already at capacity. If we don’t, we may see mortality rates similar to the peak mortality rates in Wuhan (~3%).

With the new infections that occur over the next 24 hours, we will be adding approximately 100 new hospital cases on Mar 28 EVERY HOUR.

As I have noted in my previous two posts about this topic, it is essential that policymakers act quickly to stop the spread of COVID-19. They also must act equally quickly to address the severe economic consequences for NYC’s residents. I endorse Jason Furman and my former colleague Claudia Sahm’s proposals on this topic. Moving quickly on these policies are essential if we expect people to stay at home without incomes.