to main content Putting COVID-19 Numbers and Vaccinations into Context | The Joint Commission
Improvement Insights

A critical look at latest academic and publications research including The Joint Commission Journal on Quality and Patient Safety as well as Health Research Services initiatives with partner organizations.

Putting COVID-19 Numbers and Vaccinations into Context

09/09/2021

By Scott Williams, PsyD, Director, Department of Research

As the Director of The Joint Commission’s Department of Research, I am proud to work for an organization whose mission is to improve the quality and safety of health care. But I am humbled by the health care workers who are battling with COVID-19 on the front lines every day, the infection prevention experts who have wrestled with incomplete and confusing data to help control the spread of COVID-19, and the public and private scientists in the biotech and pharmaceutical fields who have produced vaccines that are nothing short of a breathtaking accomplishment. 

Putting COVID-19 Data into Relatable Context
It is my hope that, by putting COVID-19 data into a more relatable context, people may be able to better interpret the impact of COVID-19 and to reach their own, data-driven conclusions about the role that vaccines can have in reducing risks for themselves and their communities.    

Human beings often have a difficult time putting large numbers into context. We can use language to talk about large numbers (e.g., one thousand, one million, one billion), but understanding large numbers – and making decisions about risk and reward – is not something our brains naturally do very well.    

Our perception of risk is shaped by a number of complex processes, often unconscious, that are based on:

  • emotions
  • associations
  • cultural influences 

We are hard-wired to react to threats, and our brains often take shortcuts using partial information and previous associations to help us make quick decisions about risks. These shortcuts, along with our struggle to grapple with large numbers and understand probabilities, can frequently lead us to poor decisions where risks are concerned.   

Making COVID-19 Data Meaningful
It can be hard to interpret the numbers we hear on the news, or to assess risks around things that we inherently find to be scary. For example, according to the National Weather Service, an average of 25 people each year are killed by lightning strikes. Twenty-five might sound like a lot, but we live in a country with over 330 million people! So, the chance of being killed by lightning is less than 1 in 10 million. To put those odds into context, let’s do an experiment. 

Take a deck of cards and think of a specific card. Let’s say the Ten of Hearts. Now, shuffle the deck and pick a single card. Since there are 52 cards in a deck, it should be no surprise that you have a 1/52 (0.0192) chance of picking the Ten of Hearts. Well, a 1-in-10-million chance is the equivalent of shuffling four decks of cards, calling a single card in advance, and then randomly picking that same card in all four decks!

COVID-19 by the Numbers Presentation
Our Department of Research recently developed the presentation, “Putting COVID Numbers and Vaccinations into Context.” This presentation and an accompanying video were assembled to help explain the risks of COVID-19, relative to other events such as shark attacks, lightning strikes, tornadoes, downing and traffic fatalities, and to illustrate the impact that COVID-19 vaccinations have on reducing risks. 

All data used to assemble the presentation are publicly available. The sources for the COVID-19 data came from the Centers for Disease Control and Prevention’s (CDC) COVID Data Tracker and from The New York Times’ COVID tracking data. Sources related to vaccine deaths came from the Kaiser Family Foundation and The New York Times (both of these organizations obtain their data directly from the state and local health departments that report COVID-19 data). 

Note: Data related to deaths among vaccinated people are provided as a range because all states don’t report on the vaccination status of cases or deaths. Therefore, a range was used based upon the variation observed in the states that do report these statistics.  

We hope that you will find our presentation useful while trying to help others understand the enormous impact the virus continues to have, as well as how data are proving that the COVID-19 vaccines are working. 

Please feel free to share this presentation with whomever you think might benefit from it, including your colleagues, family and friends.  

Scott Williams, PsyD, is Director of the Department of Research at The Joint Commission. In this role, he is responsible for the development and coordination of internally and externally funded research projects that promote The Joint Commission’s mission to improve the safety and quality of health care. Dr. Williams’ work has been published in the New England Journal of Medicine, Circulation, International Journal on Quality in Health Care, Psychological Reports and other peer-reviewed journals. 


1.  Brown, VJ. Risk perception: It’s personal. Environ Health Perspect. 2014 Oct; 122(10): A276–A279.
Published online 2014 Oct 1. doi: 10.1289/ehp.122-A276 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4181910/ 


2. Ellen Peters, Judith Hibbard, Paul Slovic, and Nathan Dieckmann. Numeracy Skill And The Communication, Comprehension, And Use Of Risk-Benefit Information. HEALTH AFFAIRSVOL. 26, NO. 3. https://doi.org/10.1377/hlthaff.26.3.741 https://www.healthaffairs.org/doi/abs/10.1377/hlthaff.26.3.741