Power Line

Data Suggest Masks Matter, Tests Don’t

We have posted several contributions by our friend Brian Sullivan. Brian is a serial entrepreneur who founded and now runs a cutting-edge cancer research company. He is an exceptionally able man in several respects; among other things, he understands mathematics. Unlike, apparently, every journalist in the United States. Brian has been analyzing international data on COVID-19 and has come to some striking conclusions.

One month ago, the coronavirus pandemic’s impact was still uncertain and little data was available to guide public policy decisions. Today, nearly every advanced country is touched by the pandemic, which gives us real-world data to check key assertions public health experts are making. Analysis of testing’s impact on death rates and Asia’s experience with face masks yields surprising results. Masks may be more important than testing to control COVID-19’s spread.

Trump Administration critics claim the United States’ slow roll-out of Wuhan virus tests has worsened the outbreak here and will lead to more deaths. This reflects an article of faith amongst public health experts about the need for wide-spread testing to control the Wuhan virus’ spread within a population. South Korea’s experience rapidly rolling out Wuhan virus tests seemingly provides evidence for this argument. Today, the number of new cases reported in South Korea is only 10% of the cases reported at the epidemic’s peak there 30 days ago (89 vs. 851).

If test and death rates are correlated, then it is hard to explain why countries with the two highest death rates, Italy and Spain, have per capita testing levels 30 times higher than the country with the lowest death rate, Japan. According to Worldometer, Italy and Spain have performed nearly 11,000 tests per million people while Japan has only performed 310 tests per million. The country with the highest testing rate in Europe, Luxembourg, has performed 9x the number of per capita tests than the US (36k vs. 4k) but has 2x the number of per capita deaths (50 vs. 24).

These comparisons are no fluke. A Pearson’s correlation analysis using data reported on the Worldometer website showed there is NO correlation (Pearson’s correlation coefficient = -0.01) between per capita tests performed and per capita deaths among Western European countries, Japan, South Korea, Canada, and the US. The same analysis found a high correlation (r = 0.77) between testing and cases rates, as one would expect.

What should one make of this?

First, this analysis doesn’t mean testing isn’t important. It simply highlights that more testing may not provide the benefits public health experts are touting.

Second, it highlights the speciousness of using testing as a metric to judge the Trump Administration’s response to the Wuhan virus outbreak. The data strongly suggest the slow test roll-out of testing in the US will have had no effect on the spread of the virus. Math-challenged critics find it convenient to use test numbers as a cudgel against Trump, but test numbers are meaningless as a predictor of epidemic outcome.

The only metric that matters is the number of deaths. To assess the US’s response, one should compare the number of US deaths per capita to similar countries, such as those used in the analysis above. On this basis, the US is doing well. Our per capita death rate per million is 40% (24 vs. 62) of the average level in these other countries, and 10% of the levels in Spain and Italy. Some may argue that it is too early to use our lower deaths per capita for comparative purposes. But the US recorded its first test positive case no later, and in many cases, weeks earlier, than the other advanced countries.

Third, the test data suggests we should search for other factors that may promote lower death rates. One factor may be use of face masks. In the US, until this past Friday, public health officials told us face masks were of no help. Even now, they suggest face mask use is optional. Public health experts in Asia, though, question this policy. They believe widespread use of face masks was a key factor in their reduction of infection and, ultimately, death rates.

The data from South Korea and Japan support this hypothesis. The countries have the first and second lowest per capita death rates amongst the countries analyzed but a widely divergent level of testing. South Korea has performed 30x more tests than Japan yet has a per capita death rate 6x higher than Japan’s.

Interestingly, the largest cities in each country, Seoul and Tokyo, have very low numbers of virus patients. Contrast this to the US, where our largest city, New York City, has infection and death rates 10 x the rest of the country’s.

In the United States, we are in the thrall of public health experts and their models. Dr. Anthony Fauci, the US’ leading infectious disease expert, stated on January 25th that the US had little to worry about from the Wuhan virus. Last Thursday, he suggested the country should remain under lockdown until there are no more Wuhan virus deaths. Meanwhile, the model du jour, IMHE, barely a week old, is already proving to have wildly overstated ICU and ventilator shortfalls across the country.

Perhaps these experts should look harder at the actual data, and not just their models. The data certainly suggests more testing may not be our savior. Alternatively, the Trump Administration should consider asking Governors to mandate, not suggest, that their citizens wear face masks in public. South Korea’s and Japan experience suggests that combining this policy with one that more surgically isolated the elderly and most vulnerable while allowing most of the country to go back to work, would provide more effective protection from the virus and at a far, far lower cost.

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