Of the slightly more than 30,000 total, global deaths from coronavirus to date, a third of them all have been in Italy.
That sad distinction means Italy is the source of our best potential insights about COVID19 and the risk of severe infection and death.
Colleagues reached me this morning with this March 26 compilation of coronavirus data from the Italian health ministry, when the mortality toll was at around 7000:
There are several extremely important messages in this one dense page.
1) The mean age of those dying of coronavirus was 78, and only 1.2% of all deaths occurred in those under age 50.
2) Only 2.1% of Italians dying of coronavirus were free of major, chronic diseases before- and most of those dying had more than one. In other words, being sick to start with increases the risk of dying of this new disease.
3) The percentage of those dying who were both younger (i.e., under age 50) and free of major chronic disease- was a small fraction of a percent, just as the data from South Korea have shown to date. For this group, the risk of coronavirus death appears to be very much in the same ballpark as seasonal flu.
4) The low, total number of deaths in those over 90 is a vivid illustration of the importance of "the denominator." There are few deaths in those over 90 not because the virus is gentler to them- but only because there are few people over 90 in the population to begin with. To understand the threat of coronavirus in the United States, we can't just track the severely ill in hospitals- we need good denominator data. We need to know who in the general population has it; who had it and got over it; and who is now immune. For every case we find, there may be 10, or 100, or 1000, or more- that we have overlooked because their disease is/was not at all serious. This is vital information- for your peace of mind, as well as public policy.
There are short-cuts to these data, relative to testing us all: representative, random samples around the country. Colleagues and I are working on this, but if we really do have a "Coronavirus Task Force," we would all welcome the news that they are on it, and will be sharing updates soon.
These data from Italy reinforce the promise of risk-stratified approaches to coronavirus interdiction, because our risks of severe infection and death are likely highly variable here, as in Italy. One very large portion of our population is at monumentally lower risk of severe infection and death than another. We are, I think- as I have thought all along- massively over-protecting one group and thus causing all kinds of damage by means other than infection, while under-protecting the other.
I extend my heartfelt thanks to our Italian colleagues- brothers and sisters- for these valuable data, garnered through loss and tears. I extend my heartfelt condolences to all they have been through, and are going through still. And I thank them for a data set illuminating opportunity, and hope.
Dr. David L. Katz is a board-certified specialist in Preventive Medicine/Public Health, a practicing clinician for nearly 30 years, a clinical research scientist focused on disease prevention, and co-author of multiple editions of a leading textbook on epidemiology. He is working from home, with symptoms of coronavirus infection, awaiting test results.
David L. Katz, MD, MPH, FACPM, FACP, FACLM, is the Founding Director (1998) of Yale University’s Yale-Griffin Prevention Research Center, and former President of the American College of Lifestyle Medicine. He has published roughly 200 scientific articles and textbook chapters, and 15 books to date, including multiple editions of leading textbooks in both preventive medicine, and nutrition. He has made important contributions in the areas of lifestyle interventions for health promotion; nutrient profiling; behavior modification; holistic care; and evidence-based medicine. David earned his BA degree from Dartmouth College (1984); his MD from the Albert Einstein College of Medicine (1988); and his MPH from the Yale University School of Public Health (1993). He completed sequential residency training in Internal Medicine, and Preventive Medicine/Public Health. He is a two-time diplomate of the American Board of Internal Medicine, and a board-certified specialist in Preventive Medicine/Public Health. He has received two Honorary Doctorates.