By Dr Kevin McNamee May 7, 2020
Since the beginning of the Coronavirus watch began late December, epidemiologists from many universities have created computer models to predict its transmission rates and impact upon health-care delivery system and guide policy makers.
These models are only as good as the data and assumptions used to derive the mathematical model. As computer software programmers say, put Garbage In you get Garbage Out.
The May 6, 2020 cover article in The Wall Street Journal explains the predictive models challenges and why some epidemiological models were so wrong in the initial days of the pandemic.
April predictions estimate U.S. deaths ranging from 70,000 to nearly 170,000 by mid May. Another placed that number at 135,000 by August.
The challenge is these estimates are only as good as the underlying data and assumptions. “Unfortunately the underlying data is flawed” said a senior scholar at Johns Hopkins Center for Health Security.
Modeling is a valuable tool for health providers and policy makers.
However current public policies may reflect the data and models in January and not current data. Thus the disconnect about who is at risk, what steps society should take and the measures governors should impose upon our freedom of movement.
In question is the data for the models such as unknown infection rates, cause of death may not be due to the Coronavirus or patients convinced they are infected by the Coronavirus, test negative for antibodies yet their doctor submits a diagnosis as Coronavirus.
Inaccurate data reporting causes the predictive models to be in error raising doubt about the model projection accuracy. But policy makers are making decisions based on incorrect facts and varied modeling method motivating cities to convert conventions centers and sports arenas into make-shift hospitals that were never used. Floating naval hospitals were sent to New York and Los Angeles ports to care for non-Coronavirus patients which were not used.
The American industrial know-how was unleashed to produce more ventilators. Companies pivoted from making its usual product to ventilator manufacturing. All this preparation for an overwhelming tsunami of patients that will inundate our hospital emergency rooms and intensive care units. Problem is it did not happen. Hospital emergency departments are empty. The usually full beds in the intensive care unit are empty. What happened to the media and politician driven prediction of the world coming to an end? It has not happened.
This maybe why Americans are seeing a disconnect between what is observe in their neighborhoods versus what researchers, media and policy makers are reporting.
There are many unknowns about the Coronavirus which throw off predictive models. For example, one predictive model with a value less than 1 means an outbreak is headed for control. Higher values mean significant spread.
The 1918-1919 influenza pandemic had a value of about 1.8, the 1957-1958 influenza pandemic was about 1.65, and the 2009 influenza pandemic about 1.46.
Before social distancing for Covid-19 the value ranged from 2 to 6.5 in 20 studies reviewed by The Wall Street Journal.
University of Virginia’s Biocomplexity Institute analyzed only Virginia’s cases and controls calculated predictive value of 2.2 before March 15. After March 15 it dropped to 1.1. But this raises a question of the models predictive accuracy before March 15 due to inaccurate data. Was the reduction due to social distancing or due to more and better data through Coronavirus testing?
All these models depend on correct assumptions and accurate data. Before March 15 data accuracy was at best questionable. Today, more people are being tested making the data more accurate but cause of death accuracy is still in question. Better data means more accurate predictive models.
Until then, the media enjoys high ratings by spreading doom and gloom. Governors and judges will impose the ominous weight of law enforcement and incarceration upon the people.
A judge in Texas sentenced a hair salon owner to 7 days in jail for defying his cease and desist order to close the business even though they exercised safe practices. He offered to drop the jail sentence if she “apologize” for tearing the order up, a request often asked by a parent to a child. She did not apologize stating that she and her employees need to feed their families.
She was sent to jail yet these same jails are releasing sex offenders and other high risk criminals due to fear of the Coronavirus spread among inmates.
Average American trying to restart their businesses, who are complying with social distancing, repeated cleaning of possible infected surfaces, wearing mouth and nose coverings are not allowed to open and can’t feed their families.
Public policy needs to evolve as the data unfolds. Unfortunately our courts and elected officials are making policy decisions on old predictive models that use inaccurate data and assumptions.
Yes the virus is real. People have died and continue to do so. We now know who is most at risk and can better protect them. We should make every effort to stop the spread of the virus.
My opinion is let business open if they comply with procedures consistent with reducing the virus spread. As results of this are revealed adjust the policy.
If families cannot feed themselves anarchy is not far off.