Wednesday 25 March 2020

There is no need to Panic over Coronavirus ~ but there is need to shift public health to protect the vulnerable

Ora et Labora. Life goes on. 

I like to follow statistics. For new readers I have taken doctoral levels courses in statistics, so I know a little bit about them, and how to read them. Data informs statistics and the more data we have, the more reliable statistics become. 

We need to be concerned, vigilant, and proactive. But this is NOT the Black Death.  

The key to understanding the trajectory of the coronavirus is to study reliable data coming from countries such as Italy and Germany. 

It is important to consider the influence of pre-existing conditions and comorbidities. (I should note that this morning I heard that obesity has just been very recently added as a known comorbidity). As with any coronavirus, the state of each person's immune system is also factor; those who are asymptomatic or develop only very minor symptoms. 


The following is data released March 20, 2020 from Italy based on 481/3200 dying patients:

Mean number of diseases 2.7 (media 2, SD (Standard Deviation) 1.6)

0 comorbidities: 1.2%
1 comorbidity 23.5%
2 comorbidites 26.6%
3 + comorbidities 48.6%


So how many may die? That is the question. The Infection Fatality Rate (IFR) is the way to calculate it.


The IFR is extremely important and differs from the Case Fatality Rate (CFR). The former reflects a calculation on ALL those who have been detected and undetected (including a substantial number who are asymptomatic). Based on calculations from Germany we have the following results for fatality amongst those infected: 
Therefore, to estimate the IFR, we used the estimate from Germany’s current data 22nd March (93 deaths 23129) cases); CFR 0.40% (95% CI, 0.33% to 0.49%) and halved this for the IFR of 0.20% (95% CI, 0.17% to 0.25%) based on the assumption that half the cases go undetected by testing and none of this group dies.
We can now use the German number to calculate a approximate IFR for Canada and the USA, IF rigorous social distancing is undertaken, and IF we have increased proactive testing, surveillance, and strict regional zone lockdowns (e.g. NO one is allowed to leave NYC). Otherwise hotspots will keep breaking out. 

I have read estimates that in the United States 150 million will be at one time infected. I am going to increase that to 200 million (60%). For Canada it equals 22.8 million. For Britain it is 39 million. 

The IFR for the USA is: 400,000
The IFR for Canada is: 45,600
The IFR for the United Kingdom : 78,000



The BAD news is that given the lack of data, the above EXCLUDES those who have a comorbidity. The "good" news is that with experimentation with antivirals, prophylactic interventions, and potential vaccines coming next year, the numbers will come down. 

The first wave we are presently seeing is the worst since there were no measures in place to mitigate transmission. We now know that coronavirus was being widely spread in January all over Europe and North America. Based on this it is has been estimated that at least 50% of the population may be asymptomatic. After the initial lockdown which should flatten the curve, medical services and supplies can then be freed up to care for a steady stream but more predictable stream of sick patients.  

Late April, early May (at the very latest) will be the time for us to get back to work, to life. Measures should be in place by then to protect the vulnerable. Those persons who are in the above categories will have to make serious changes in their lives. 

4 comments:

John Haggerty said...

A lucid analysis.

My only acquaintance with your subject is *Statistics. A Very Short Introduction* by David J Hand published by the Oxford University Press.

These Short Introductions by Oxford cover a wide field ranging from Judaism to the Roman Catholic Church and the Reformation, from Cloning to Schizophrenia and Quantum Theory.

Professor Hands raised the tragic case of a woman in England who was convicted of murdering her child. Her first baby had also died suddenly.

A doctor distinguished in his field told the court that the likelihood of two cot deaths in a row was statistically impossible. The woman served some years in prison and was brutally treated by other women prisoners.

It was a statistician who helped clear the woman's name, pointing out that the doctor was not competent in analysing the statistical samples of cot deaths throughout the world. The woman was released but did not live long.

It made me wonder just how competent government ministers and civil servants are in their grasp of statistics. Even a doctor can misread the data in his own field. Basic statistics should be taught in high schools.

Barona said...

John,

I don't know what the thinking is in Scotland. But here, the "misleader" has told Canadians to "go home and stay home". No plan, no vision, no leadership.

The fact is that we MUST start to rev up the economy by May or it will precipitate an intolerable financial crisis: which will lead to many, many deaths; direct and indirect.

I find it extraordinary that Doug Ford is shutting down all of Ontario which is huge. Saskatchewan and manitoba have very, very few cases. In fact, outside of the major cities, there is very little coronavirus. There should be very strict inter-provincial travel, there should an increase in testing and community surveillance. Such proactive measures would cost a lot of money, but far, far less than shutting most of the economy.

Money is needed - real money - not phony computer generated entries - to fight this virus and restart the economy.

You will notice that the opinion to sit and do nothing, to hide under the bed mostly comes from those who are on "white collar welfare", quote unquote "working" (directly or indirectly) for the Government. For those who actually do something - especially small business - this situation is intolerable.

Now that we know much more about the disease we can respond in a proactive manner. We know much more than we did even a day or so ago.

John Haggerty said...

Yes, Barona, in Scotland and the rest of the United Kingdom it is *go home and stay home*.

The streets of Glasgow's West End were ghostly when I went out for my stroll. The grocery stores only allow a few in at a time. The young women working in my store were students and very cheerful. Small things count.

White collar workers are in a privileged position as you say. Not so train and bus drivers, nurses, doctors, building site workmen, power workers.

Nigel Farage on YouTube asks what provision will be made in Britain for millions of self-employed. He asks why the big jets are bringing in visitors from abroad, who will mingle freely in London before being told to *go home and stay home*.

Your fear of economic collapse is what some call Economic Armageddon. I did not know Ontario had shut down. Cities will be the epicentre of COVAD-19 in Britain. London in England, Glasgow in Scotland.

Right now feels like the phoney war my parents lived through after September 1939. I can think calmly and coldly in these moments, but my fears are for those in essential services, and for economic collapse like 1929 or worse.

In late January I had a wonderful school reunion, sharing a cab home in the wee small hours with someone I had last seen in 1968, now a beautiful woman in her 69th year, my age. We talked about Twiggy and Dusty Springfield!

None of us from the class of 1963 at Saint Pius X School were aware of COVID-19. The reunion now feels like Goodbye To All That. Our day is done.

I am thinking of T.S. Eliot: *The end of all our exploring is to arrive at the place where we started and know it for the first time.*


Everyday For Life Canada said...

When this corona virus clears and it will, I think we will realize that the cure turned out to be much worse than the infection.