9 Apr 20
Nobody expects a drama teacher or a journalist to be conversant with distribution functions. After watching Canada’s Chief Public Health Officer, Dr. Theresa Tam, inform the media of expected progress of the CONID-19 pandemic, I’m not sure she understands them either.
For example, Dr. Tam showed three distribution curves of different scenarios. These curves strongly resembled bell curves, or Gaussian distributions. A Gaussian distribution has three variables: one we can identify as time, and the others are expectation value and standard deviation. Dr. Tam did not clearly explain that the standard deviations, and times at which the expectation values occurred were even more speculative than the expectation values themselves were.
The expectation values of infection cases were merely scenarios – what if 1 to 10 percent (an order of magnitude, BTW), 25 to 50 percent (another huge range), or 70 to 80 percent of the population were infected. But no explanation was given about time of maximum, or standard deviation. These variables were picked out for illustration purposes only, and were not based on real data. These curves were models all right, but they unmoored from reality. They served as impressive looking hand-waves that made wild guesses look impressive.
Another chart showed that Canada began strong mitigation measures well before the number of cases appeared above zero on the graph. The question then arises, how could transmission from practically no one to tens of thousands occur in the face of strong isolation measures that began March 10th? And, given that an isolation of 14 days is sufficient to prove infection or not, how can infection continue to spread according to her graphs over multiple fortnights in the face of strong mitigation?
Another problem with Tam’s presentation was her estimate of deaths. How were her numbers arrived at? She used a morbidity ratio of 2.2 % for the April 16 estimate, but 1.17 % for 80 percent of the population getting infected. Morbidity is not the same across each demographic, so how was the morbidity rate estimated and total number of deaths calculated?
Dr. Tam scared the hell out of the journalists but did so, not with data, but on the weight of her authority and with the aid of graphs that did nothing but illustrate scenarios. The actual data, of cases since March1st, is pretty thin, and the plot shows a curve levelling off on April 14th, with precisely 22,580 cases and 500 deaths. What if this is the actual scenario?
Dr. Tam used a common trick of giving very precise numbers to bolster credibility. She “forecasted” 22,580 to 31,850 cases by April 16, when she ought to have said 27,000 plus or minus 4,000, or from 23,000 to 32,000. This still gives the estimate of 500 to 700 deaths. One has to wonder if Dr. Tam really understood that trickery to impress - giving falsely precise numbers - was at work in her presentation.
Dr. Tam was relentless in her virtue-signalling and her insistence that we keep the country shut down. The curves, she said, showed “critical outcomes, resulting in DEATH. These STARK numbers tell us we MUST do everything we can NOW to remain in that best case scenario, to stay in the lower range, WITH STRONG EPIDEMIC CONTROLS. Our collective effort, DESPITE ALL THE HARDSHIP AND COSTS, is CRITICAL as we MUST minimize the population infected IN ORDER TO KEEP DEATH, admissions, and hospitalizations AS LOW AS POSSIBLE. The resolve and the level of effort of all Canadians from our health care workers on the front lines to public health authorities to all Canadians who are practicing physical distancing will ultimately determine if we remain in this best case scenario and ensure that our health system can cope. WE CANNOT PREVENT EVERY DEATH, BUT WE MUST PREVENT EVERY DEATH THAT WE CAN!”
I think history is going to show that we destroyed our economy for next to nothing. But no one is going to blame Dr. Tam that her moralistic insistence on mitigation destroyed the economy because the economy is not her lane. No one will blame Mr. Trudeau for not getting a second opinion. Anyhow, the evidence is there that Dr. Tam is making wild guesses at the cost of our economy, and that the Prime Minister is content to let strong women run the country with him as the titular head.
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