Coronavirus Chronicles — The Limits of Testing

Back in April, writer Nate Silver made the sensible argument that “the number of COVID-19 cases is not a very useful indicator of anything — unless you also know something about how tests are being conducted.” He speaks of incomplete data, which conceals systemic and logistical problems that are too easily ignored.

For instance, in far too many locations, the medical personnel are being run ragged. Testing gets done as part of the triage process, to determine who needs immediate help the most. Silver points out that the frontline people are not focusing on the creation of a “comprehensive dataset for epidemiologists and statisticians to study.” They are a bit too busy trying to make sure that patients are discharged to home rather than the morgue.

And yet, the resulting numbers are not regarded as best guesses, or as sincere but possibly incomplete efforts, but as gospel carved in stone, with several types of experts eager to provide interpretation. So, what kinds of problems are we letting ourselves in for by tolerating this much slack? Silver wrote,

A country where the case count is increasing because it’s doing more testing, for instance, might actually be getting its epidemic under control. Alternatively, in a country where the reported number of new cases is declining, the situation could actually be getting worse, either because its system is too overwhelmed to do adequate testing or because it’s ramping down on testing for PR reasons.

Yes, the author “went there.” The public relations angle, or spin, is always an important, if unwelcome, part of the news-scape. When spokespeople have ego-inflating authority, and jobs from which they could be fired or unelected, they do not always adhere strictly to the truth. What is the use of hiding from that reality?

But leaving unworthy motives aside, it appears possible to deduce many different conclusions from what are, perhaps, too easily accepted statistics. For instance, here is a fairly mind-blowing bit of news from Imperial College London scholars, who guess that…

[…] the true number of people who had been infected with the coronavirus in the U.K. as of March 30 was somewhere between 800,000 and 3.7 million — as compared to a reported case count through that date of just 22,141.

That estimate, if accurate, would differ from the official count by several orders of magnitude. And, no matter what kind of testing is done, the individual benefit is not enough. This personal matter needs to also be a public health matter. People demand answers from science but resist providing the information needed. A large part of the value of testing is lost unless the accurate and complete numbers are passed along to trained statisticians who know how to extract meaning from them.

Your responses and feedback are welcome!

Source: “Coronavirus Case Counts Are Meaningless,”, 04/04/21
Image by Delaware National Guard/Public Domain

Leave a Reply

Your email address will not be published. Required fields are marked *

FAQs and Media Requests: Click here…

Profiles: Kids Struggling with Weight

Profiles: Kids Struggling with Obesity top bottom

The Book

OVERWEIGHT: What Kids Say explores the obesity problem from the often-overlooked perspective of children struggling with being overweight.

About Dr. Robert A. Pretlow

Dr. Robert A. Pretlow is a pediatrician and childhood obesity specialist. He has been researching and spreading awareness on the childhood obesity epidemic in the US for more than a decade.
You can contact Dr. Pretlow at:


Dr. Pretlow’s invited presentation at the American Society of Animal Science 2020 Conference
What’s Causing Obesity in Companion Animals and What Can We Do About It

Dr. Pretlow’s invited presentation at the World Obesity Federation 2019 Conference:
Food/Eating Addiction and the Displacement Mechanism

Dr. Pretlow’s Multi-Center Clinical Trial Kick-off Speech 2018:
Obesity: Tackling the Root Cause

Dr. Pretlow’s 2017 Workshop on
Treatment of Obesity Using the Addiction Model

Dr. Pretlow’s invited presentation for
TEC and UNC 2016

Dr. Pretlow’s invited presentation at the 2015 Obesity Summit in London, UK.

Dr. Pretlow’s invited keynote at the 2014 European Childhood Obesity Group Congress in Salzburg, Austria.

Dr. Pretlow’s presentation at the 2013 European Congress on Obesity in Liverpool, UK.

Dr. Pretlow’s presentation at the 2011 International Conference on Childhood Obesity in Lisbon, Portugal.

Dr. Pretlow’s presentation at the 2010 Uniting Against Childhood Obesity Conference in Houston, TX.

Food & Health Resources