Would more testing help in North Carolina?

Since my last post, Governor Cooper postponed the transition to Phase 3 at least until July 17th. Our analysis suggests that this was indeed the right thing to do. However, with no further action, pushing the date to July 17th only is not going to help.

Let us continue from where we left off. The figures in my last post showed that even with 60K daily testing capacity and staying on course in Phase 2 there will be a significant increase in hospitalizations and deaths as we go into Fall. Would more testing help? The following figure looks at how the total number of deaths would change with different testing capacities and under different assumptions on what the state chooses to do starting with July 17th. (Note that this is an efficient-frontier plot, not a plot of deaths over time.) We assume that the state sticks with whatever it chooses to do at that date until the end of the year. Of course, that is not going to happen and the state will respond to changes but this analysis helps us get an insight into how things would generally look like.

In the figure, x-axis indicates the degree of relaxation from stay-at-home phase, where 0% corresponds to stay-at-home level and 100% corresponds to life as we lived before the pandemic. Now, there is significant uncertainty as to what level of relaxation each phase corresponds to but the mobility data suggests 25% for Phase 1 and 50% for Phase 2 look reasonable. Of course, mobility does not directly translate to infections and so we should acknowledge that we might be overestimating these relaxations a little bit. However, we also do not see much evidence of wide adoption of face coverings in North Carolina and so it is not clear how big of an overestimation this is.

With the caveat above, what we see here is that it is impossible to go back to life as usual even with significantly high levels of testing capacity. But perhaps, with clear attention to social distancing measures, if we can bring down the infection rates to what we have observed in Phase 2 so far, we might be able to significantly lower the number of deaths. (See the red curve at the very bottom.)

One thing we haven't addressed yet though is contact tracing. More testing is useless without sufficient contact tracing and unfortunately things do not look good there. I will soon share our findings on that.

What is happening in North Carolina?

We have been working on using our model for North Carolina, where hospitalizations have been increasing consistently. We will be sharing a summary of our results soon with a paper but here are two figures which provide some idea as to what we see.

North Carolina is set to move to Phase 3 on June 26 but there is a possibility that Governor Cooper might decide to extend Phase 2. In the figure above, we are looking at three possibilities: the state moves to Phase 3 starting with June 26, stays at Phase 2, or moves back to Phase 1 until the end of the year. I do not think there is a serious possibility of going back to Phase 1 or staying in any one of the phases until the end of the year but they are useful for understanding the impact of different decisions. The figure strongly suggests that moving on to Phase 3 will be disastrous. In fact, even staying in Phase 2 will likely result in a significant increase in the number of deaths and hospitalizations peaking some time in Fall.

The figure above assumes a testing capacity of 30,000 per day, which is a little more than the maximum number of tests performed on a given day so far in North Carolina. If we double the testing capacity, it certainly helps but moving on to Phase 3 or staying on course in Phase 2 will again result in major increases in deaths and hospitalizations over the course of a few months. You can see that in the following figure.

 

More to come soon...