Numbers can tell us a lot about pandemic
Although the COVID-19 epidemic is still unfolding, we’re gradually learning more about the virus and how to combat it. Let’s look at what the numbers tell us.
I’ll start with what we know for almost certain. (“Almost”, because every day brings a new revelation that casts doubt on prior assumptions.)
First, those Canadians most vulnerable to serious illness and in some instances death, are elderly. In B.C., the average age of death from COVID-19 is 85. There have been virtually no fatalities among people under 40.
Second, by far the majority of fatalities, countrywide, have occurred in nursing homes. As of May 25, 81 per cent of deaths were recorded in these facilities. Five nursing homes have lost more than 40 per cent of their residents to the virus (all were in Ontario and Quebec.)
After that, things grow progressively less certain. Does shutting down various sectors of the economy and imposing social distancing work?
With near certainty yes, if you mean does it reduce the number of infections. But if you mean does it reduce the death rate, that is less clear.
Let’s start with B.C. and work outward. Initially, when the disease first appeared, the number of infections in our province climbed rapidly from a handful in February, to between 65 and 90 per day between midMarch and late April.
At that point the shutdown took effect, and over the following two months, the daily rate subsided, rarely exceeding 20, and usually fewer. Is that evidence the policy worked?
I believe so, because as soon as the shutdown was eased, the infection rate began to creep back up again, reaching about 40 a day in late July and the mid-80s in August.
This would seem to suggest the hard shutdown did indeed flatten the infection curve. That was important early on, because it was feared a flood of infections would swamp our hospital system.
But now the death rate. From a height of six per day in early April, fatalities declined in a more or less straight line thereafter, with scarcely any recorded in the last days of July and early August (the most recent data I have).
That is to say, the death rate did not rise as the shutdown was lifted. Instead, it fell. The same is true of hospitalizations. (The number of COVID patients currently in hospital, as of Aug. 6, was 13.)
There are several conceivable explanations.
Maybe those most vulnerable to the disease died early in its onset. Certainly that happened in nursing homes.
Or instead, perhaps our modes of treatment have improved. That seems likely.
But there’s a different possibility to consider. Perhaps, all along, death rates were not particularly sensitive to blunt measures such as shutdowns. Maybe, these are not so effective as we thought.
So far, these are B.C. numbers only. Some other jurisdictions, notably the U.S., are seeing different results.
Nevertheless we can bolster this suggestion. A study published in the British medical journal The Lancet on July 21 examined the experience of the top 50 countries ranked by their number of COVID-19 cases.
It found that high numbers of deaths were associated with increased obesity and large disparities in income. This might explain, in part, why fatality rates in the U.S. are higher. That country leads most developed nations in obesity and income inequality.
On the other hand, the study found that rapid border closures and full lockdowns did not affect death rates. At a minimum, that should be food for thought.
Where does all of this leave us? Clearly, nursing homes should remain our immediate centre of attention. Everything possible must be done to make them virus-proof.
And elderly Canadians should be advised to take extra care.
After that, though, the uncertainties mount. If fatalities remain low, but the infection rate rises, even to pre-shutdown levels as it is now doing, are we willing to inflict further economic and social turmoil to deal with this?
At some point, we’re going to have to normalize a disease that might be with us for years. That might mean stratifying the population, with more comprehensive protections for those at serious risk, and less-intrusive measures for those who are not.
And don’t pin your hopes on a vaccine. Canada’s chief public health officer, Dr. Theresa Tam, has warned that if one is found, it’s unlikely to represent a silver bullet.
Personally, I would want to see much stronger evidence that large-scale shut-ins will suppress fatalities in jurisdictions such as B.C., before going this way again.
Easily said, of course. As someone who ran B.C.’s health ministry once upon a time, I know how much more complex things look from the inside than they do from outside.
I’m also aware how little room to manoeuvre public health officials such as Dr. Bonnie Henry and Health Minister Adrian Dix have in a climate of fear and near panic.
All the more reason to keep the debate focused, as much as possible, on what the data are telling us.