William Cayley: Statistics are people too

In our ongoing preoccupation with the number of “cases” of covid-19, we must not forget that behind every number is an individual, says William Cayley

bill_cayley_2“There is strength in numbers.” This well worn aphorism usually calls to mind images of armies, teams, or other large groups of people undertaking a challenge. It reminds us as well that statistics allow us to count, to document, and to understand.

Despite Mark Twain’s feelings on the subject, the value of statistics is nearly undisputed in today’s world—we use and rely on them far more today than Twain could ever imagine. Indeed, the current covid-19 pandemic has proved to be a real life, real time education in statistics and epidemiology for both professionals and the general public. Only a few months ago, a news story on “flattening the curve” would probably have been taken as reporting on local roadways, and yet there are now daily reports in the news on the latest covid-19 statistics.

These numbers are clearly important. They help those who are responsible for making decisions to understand what is transpiring, and hopefully help guide wise decisions. They help those of us on the frontline think about what may lie ahead, and how to prepare at work and at home. However, they can also still obscure just a bit the underlying truth they represent.

It is startling to see the daily increase in worldwide case counts of covid-19. It becomes even more staggering to consider these numbers when one stops for just a moment, and considers what each one of those numbers represents. 

As the global case count grows, we need to recall that each of those “cases” is an individual—a person with a unique story, with a lifetime’s worth of hopes, fears, uncertainties, and anticipations. More than that, none of those numbers really represents just an “individual,” each number represents someone’s son or daughter, husband or wife, or sibling. Each number represents someone in a network of relationships and interdependency.

It goes beyond just the raw numbers. When preparing a lecture on covid-19 two weeks ago (one that is now hopelessly out of date!), I had to refresh myself on some basic epidemiology, including the significance of R0 (“the average number of people who will catch a disease from one contagious person.”)

As a doctor I find it useful to know that covid-19 is considerably more infectious than seasonal influenza, but as a father and a husband I am reminded that an R0 of 2 to 3.5 means that if I contract covid-19, I will most likely sicken at least half of my family. 

Flattened curves, while desirable epidemiologically, also tell us that our adherence or non-adherence to social distancing and all sorts of other nuisances can make the difference between being busy versus being overwhelmed for us and our colleagues, and the difference between life and death for some of our friends and family. 

Statistics are useful, they can be descriptive and perhaps even predictive, but fundamentally we need to remember that behind each and every number we count (in medicine), lies a unique person with his or her own individual story.

Statistics are people, too.

William E Cayley Jr is a clinical professor at the University of Wisconsin, Department of Family Medicine and Community Health. Twitter @bcayley

Competing interests: I declare that I have read and understood BMJ policy on declaration of interests and I have no relevant interests to declare.