Coronavirus — Why aren’t we doing random sampling? Is it crazy not to?

Thinking Citizen Blog: Thursday is Health, Health Care and Global Health Policy Day

Are we making massively consequential decisions without reliable data? Why aren’t we doing random sampling instead of testing only the sick? What countries are doing it right? Today, excerpts from an article by USC professor Neeraj Sood. Experts — please chime in. Correct, elaborate, elucidate.

WHAT ARE THE REAL INFECTIVITY AND MORTALITY RATES?

1. “Testing only sick or symptomatic patients will not get us to the truth. To see why who we test matters, consider the flu.”

2. “Its mortality rate is around 0.1% — meaning that of everyone infected with the flu, tested or not, 1 in 1,000 die of it. If we only tested people who are hospitalized with flu-like symptoms, the mortality rate jumps 75-fold.”

3. “Similarly with the coronavirus, testing only sick and symptomatic people will result in an overestimate of mortality, which would heighten fear and anxiety and worsen their economic effects.

RANDOM SAMPLING IS THE ONLY WAY TO LEARN THE TRUTH

1. “The way to learn the truth is to test a random sample of the population in major cities with an outbreak.”

2. “Random testing would reveal the true mortality rate and also how many people have the virus, an important factor in determining its infectivity.”

3. “Authorities need to start conducting random testing now, with statisticians in the coronavirus command center guiding the design. If the infectivity and mortality rates turn out to be similar to those of the flu, this approach could avert billions of dollars in economic loss and calm public fears.”

TO ISOLATE THE INFECTED DON’T RELY ON VOLUNTEERS

1. “In this regard, it is unclear that relying exclusively on people who are volunteering for the tests makes sense.”

2.”These are probably people who are exhibiting symptoms and heeding public-health messages to isolate themselves at home, as they would do for seasonal flu.”

3. A study of flu-vaccine strategies (of which I am a co-author) shows that self-selection doesn’t get at the high-risk populations.”

NB: In the second link, John Ioannidis, a professor at Stanford, makes a similar point.

“The data collected so far on how many people are infected and how the epidemic is evolving are utterly unreliable. “ (3/17/20)

Opinion | It’s Dangerous to Test Only the Sick

In the coronavirus pandemic, we’re making decisions without reliable data