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.