Key messages by Mostashari and Emanuel:
The first two questions, which will be key to guiding policymakers on whether the extreme measures taken to suppress the outbreak are working, are these: Is the Covid-19 outbreak in a city or state getting better or worse? And how fast?
To know if Covid-19 is getting better or worse, we need to know how the percentage of positive cases — not the number — changes day by day, accounting for delays in testing and reporting and how the percentages change in response to public health measures such as sheltering-in-place or suppression. This will tell us how effective these measures are in curtailing the spread of SARS-CoV-2 and thus whether when social restrictions could be relaxed or additional policies might need to be implemented.
The other two questions that need answers are essential for guiding doctors in their medical decision making: Who is getting Covid-19? And what are their outcomes?
First, as a condition of receiving approval and test kits, laboratories should be required to submit basic information like age, county of residence, and testing site on every person tested — not just the positives.
Second, we need a sero survey of multiple communities. Such studies test blood samples from randomly chosen individuals in a defined population. This is the way to assess the real percentage of people in a community who test positive for recent coronavirus infection. This gives a picture that is wider than just the individuals who are bringing themselves in for testing. Right now we simply have no idea how many Americans are infected with the coronavirus. This will be a key input to models trying to predict when herd immunity can begin to blunt the outbreak.
PS. An epidemic calculator
PS. Current situation of the pandemic in our country.
