On Being a "Numbers Person" in the Covid-19 Era

On September 8, 1994, my husband and I traveled with our 3-year-old son and his 9-month-old twin brothers to my parents’ home near Rhode Island. Waiting at the airport for our red-eye flight to the airline’s hub in Pittsburgh, we learned that a plane bound there, operated by the same airline, had crashed in the woods a few hours earlier, killing all 132 people on board. When we arrived at Green Airport the next morning, I was surprised to see a television crew waiting for us. “Were you frightened?” a reporter asked me. I had been up all night with three small children and said the first thing that popped into my head. “No, I wasn’t frightened,” I replied. “It’s a low-probability event.”

My calm response aired that evening, alongside that of a woman who was sobbing. “Oh, those poor people!” she cried. Of course, I had not been asked whether I was sorry for the loss of life; I had been asked if I was frightened by the crash, and statistically, there was no reason to be. Yet, with some amusement, I realized that sometimes, being a “numbers person” can make one appear to be … well … a little uncaring.

I have sensed this perception in responses to biostatisticians who have questioned the evidentiary basis behind governmental response to the Covid-19. Some appear to suggest that these biostatisticians are unaware of either the numbers of “coffins of Covid-19 victims” or the exponential nature of infectious disease transmission that puts an increasing number of people at risk of death. I would suggest the opposite is true. The issue is, it seems to me, not lack of awareness; it is a heightened awareness that defies comfort—an all-too-complete picture of the consequences, not just of the disease, but of the lockdowns intended to combat it.

When I hear calls for protection of the vulnerable, I echo them, of course. But which vulnerable people? We are all familiar with the demographic and clinical conditions that put one at higher risk for severe Covid-19 illness. Yet, as I write this, an estimated 22 million U.S. residents have been laid off because of business and school shutdowns, and more layoffs are coming. If prolonged, the resulting economic deprivation will dramatically increase their risk of numerous negative health outcomes, including a doubling of their odds of cardiovascular disease, our nation’s top cause of death. The immunosuppressive effects of chronic stress are well-documented, ironically meaning that some paycheck-to-paycheck earners may be put at a heightened risk of infection from the very policies intended to help them avoid it. Suicide hotlines are already seeing spikes in calls from persons who are anxious, isolated, or worried about their economic futures, and persons of low income and educational levels are reporting more financial stress than are their higher-income/education counterparts.

Covid-19 is an important public health issue. So, too, are unemployment, cardiovascular risk, chronic stress, loneliness, and despair.

What is the actual risk associated with Covid-19 infection? Legitimate questions on this point merit more than the usual vague bromides about listening to “the experts.” One might first ask, which experts? From the beginning of the Covid-19 outbreak, most top biostatisticians have been making essentially the same observations: (1) without an accurate denominator of the total number of infections, both symptomatic and asymptomatic, it is impossible to estimate disease severity; (2) it is important to account for sources of regional variation (e.g., population age, hospital bed occupancy) and competing causes of death (i.e., not every death with Covid-19 infection is a death from Covid-19 infection); (3) despite media coverage suggesting otherwise, the risk of Covid-19 death is remarkably low for those not in the known vulnerable groups; and (4) exaggerated estimates of harms and some extreme measures themselves can be harmful to public health (e.g., public panic, hoarding of essential supplies). Elsewhere, a research intern and I observed that the Imperial College model that was the basis for the shutdowns did not meet fundamental professional standards and had likely systematically overestimated projected ICU stays and deaths. A much higher-quality model from Oxford reached very different conclusions and, in a sign of a solid evidence-based approach, called for population serological surveys to validate or refute the modelers’ results. Other experienced modelers are examining disease trajectories by country, finding few differences between countries with versus without lockdown policies.

All this evidence is preliminary, and there is certainly no shortage of disagreement about data interpretation. We do not yet have the most important information needed, estimates of disease severity with accurate denominators, although one preliminary study in the Gangelt region of Germany based on antibody testing concluded that the infection fatality rate was 0.37%. While we wait for more antibody test results, what is a “numbers person” to do?

For a “numbers person” who has the misfortune of having a tender heart, as I do, watching the unfolding of a process not based on reliable evidence has been difficult. The policy disagreement has never been about whether we "social distance." It has always been about how we do so, and whether reliance on better evidence could have produced more targeted, smarter strategies with less collateral damage to our nation's economically vulnerable.

In that context, it seems to me that the best response of a “numbers person” is to rely on the methodologically higher-quality work in reaching conclusions about Covid-19, update those conclusions as new evidence comes in, and advocate for highest-quality data to support decision making. Lest that sound too much like my measured response to the reporter 25 years ago, I would suggest that when one considers the harms as well as the benefits of Covid-19 lockdowns, calling for an evidentiary basis for decision making is the very opposite of uncaring. It is, in fact, the only caring thing for a "numbers person" to do.