Author: Dr. Jim Chastain | PE, BCEE, MPH

COVID has brought the concept of ‘risk’ front and center in the minds of Americans. News reports, governmental mandates, workplace policies, social media, and personal conversations bombard us with very mixed messages about the true risk to life and health that COVID presents. Individually, we must process that information to form our own opinion as we conduct our daily lives. 

Evaluating and Communicating Risk

Risk perception is a peculiar concept, though.  While risk levels can be evaluated and expressed objectively, ultimately individual actions (or fears) tend to be psychological phenomena.  In formal public health programs, most students have at least one course in Risk Communication.  Its purpose is to teach the principles of effectively translating the findings of technical medical/statistical evaluations into common language generally to advocate a course of action.  You learn this is not easy.  Most people just want the ‘bottom line’.  Journalists want ‘sound bites’ that entice readers or viewers.  Policy makers are inclined to facts that support a position. In reality, the technical results tend to be highly nuanced, so crafting ‘the message’ can be challenging.

In general, the message should state the findings of the reports (usually averages) and identify areas of confidence and areas of uncertainty.  All studies have limitations and those should be disclosed.  The objective is to convey what we know (and don’t know) clearly and transparently to build trust and provide a basis for decision making. In a pandemic event like COVID where the dynamics of the disease were unknown, this is a particularly challenging, if not impossible, task.  

However, as more data has become available, we should be able to get a better picture of where the true risks lie and better inform the decision process.  While different variants present themselves, the basic outcomes are tending to stabilize which should provide a better basis for action.  Further, the vaccines and, now therapeutics, can provide the guidance (and hope) that many seek.

Navigating Media Messaging

Because of the inconsistent messages in the media, the prudent person must become an informed consumer of information…in other words caveat emptor.  Educate yourself.  Become proactive in looking at sources of claims and thinking about risks.  Look up the actual health statistics and form your own opinion.  To do this it is also helpful to compare the COVID risks to other risks that we’re used to dealing with.  Part of the initial challenge with COVID was that there was no frame of reference.  Now we’re beginning to get some landmarks to guide us. Because data can be difficult to navigate, here are a few suggestions.

  1. Focus on the mortality (death) rate as opposed to the case count.  The mortality rate is probably the most accurate ‘end point’ we have in the data reporting process.  Hospitalization rates are important and helpful for health care planning, but to my mind the mortality rate is the statistic which is of most concern to people. Because COVID testing has been inconsistent at best, I don’t see COVID case count as a useful statistic for reliable risk evaluation.  That’s not to say it isn’t important, but effective disease screening has been a major weakness throughout the pandemic.  We really don’t know how many people have had COVID but went undetected (and thus are not likely to be reinfected).  While some smart people have worked to develop estimates with the available data, I choose to focus on the mortality rates.
  2. Understand that there is no one statistic that completely characterizes the COVID risk and impact.  At a minimum when evaluating the data, you should look at (a) total change, (b) percent change (c) size of the sample and (d) mortality rate per 100,000 population.  For example, a city with 1,000,000 people can have mortality rate of 10 people one week and 20 people the next week.  That can be reported as a 100% increase in the death rate or alternatively as an increase of 10 people deaths in a 1,000,000 population.  The number of automobile accidents may have been more than that.  However, if the population of the city was 10,000 rather 1,000,000 the meaning of 10 deaths is much different.  Thus, the way the message is presented can meaningfully drive the risk perception.  (As a caveat, technical professionals will be actively evaluating these trends relative to the epidemiological curve, but the point here is that it generally takes several views of the data to assess the data).
  3. Somewhat similar to that above, one of the first rules of biostatistics in epidemiology is to stratify the data.  This means that at a minimum we should evaluate the death rate based on age and sex in an effort to flesh out vulnerable population groups. More detailed studies will also look at race, location, economic classification and so forth.  Stratification helps characterize disproportionate risk in the population. The policy focus should be on high-risk areas. While looking at overall numbers called ‘crude rates’ (i.e. total deaths/total population) are easy, the valuable insights come from stratified analyses.
  4. Where do you look for the data?  Regardless of your opinion of their handling of the COVID program, the most of the reliable data tabulations reside with the CDC or state health department (in my case the Florida Department of Health). I find it easier to locate data in the National Center for Health Statistics ( than CDC general website site but that’s just personal preference. State and federal regulations mandate that heath care providers are to report outcomes according to standard protocols. Even with the NCHS summaries though, the amount of data is mind numbing.  Computational summaries of these sources in secondary references can be convenient.
  5. How do the risks (mortality rates) for COVID compare to other causes of death which are more familiar?  Again, the CDC and FDOH maintain records of death rates ‘by cause’ which can be useful in providing perspective.  A convenient comparison is the influenza mortality rates since most people have developed some level of personal risk tolerance with the flu.  There are significant differences in context (COVID is at pandemic stage, flu is endemic), but that’s the point of risk evaluation.  Automobile accidents, heart attacks, cancer, homicides, etc. are also risks and life must be lived among them all.

Sometimes what you find is surprising.  For example, did you realize that the leading cause of death in the US in 2020 (last full year of data) for adults aged 18-45 was Opioid (fentanyl) overdose? …over three times the level of COVID.  That shocked me.  Why isn’t that receiving more attention?

Beginning Your Own Research

As a starting point, here are a few links to check out. 

A few comments…

  • Lower mortality rates (deaths/100,000 people) are indicators of lower risk.  Mortality rates can vary by time, location and by COVID variant. 
  • For graphs, pay attention to the numbers (scale) on the Y-axis; don’t just look at the shape of the curves.  It’s not unusual for different graphs to have different scales so if you just look at the shape of the curve you can misinterpret the message.
  • Odds Ratios are a way to compare probabilities/risks between two different categories.  In the research article (NCBI/NLM/NIH) comparing COVID to season flu, to the extent that the Odds Ratio is less than 1.0 the death rate is higher for flu.  Odds Ratios greater than 1.0 means that the death rate is higher for COVID.  Maybe this will help clarify the risk context for you and various members of your family.  Notice that the article identifies assumptions and limitations of the study.
In Summary…

The point of this exercise is to invite you to be curious, even skeptical, of any report that you read.  We don’t live in a riskless world. Every decision (pro or con) has a risk of some type associated with it. The objective is to allocate your risk intelligently. Therefore, seek to understand the data and assess its truthfulness and transparency.  Inform yourself of the critical metrics and decide how you want to evaluate the options. 

You probably do this when you’re shopping for a car…maybe it’s a good thing when protecting your health, too. In the end, you may make the same life choices as before, but this will help you more intelligently balance data, uncertainty, responsibility, and fear.

“The point of this exercise is to invite you to be curious, even skeptical, of any report that you read. We don’t live in a riskless world. Every decision (pro or con) has risk of some type associated with it. The objective is to allocate your risk intelligently.”

– Dr. Jim Chastain

Dr. Jim Chastain is a Senior Consultant at Chastain-Skillman, specializing in various fields of engineering which include computer simulation modeling of hydraulic systems, feasibility analysis, and water infrastructure design and permitting. He holds a Master’s and Ph.D. in Public Health from the University of South Florida, as well as a Bachelor of Science in Civil Engineering and Master’s in Environmental Engineering from the University of Florida.

Dr. Chastain has 49 years of professional experience in engineering and planning as a consultant to both government and private industries. In addition to his professional experience, Dr. Chastain also lends his extensive knowledge of engineering to the academic community as a guest lecturer at both the University of Florida and the University of South Florida.


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