Responsible SciComm

One of the things I’ve written about on this blog quite frequently is how important the treatment of uncertainty is in science, both in the application of the scientific method itself and in the communication of results to a wider audience. This blog post makes a similar point about the presentation of results from modelling the spread of Covid-19.

Yesterday, a group in Oxford released a paper that implied that a signifcant fraction of those in the UK may already have been infected. This was quickly picked up by numerous media outlets who highlighted that coronavirus could already have infected half the British population. James Annan has already discussed it in a couple of post, but I thought I would comment briefly myself.

To be clear, I certainly have no expertise in epidemiology, but I do have expertise in computational modelling. So, I coded up their model, which is described in Equations 1-4 in their paper. They were also doing a parameter estimation, while I’m simply going to run the model with their parameters.

The key parameter is $latex rho$, which is the proportion of the population that is at risk of severe disease, a fraction of whom will die (14%). They explicitly assume that only…

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11 Responses to “Responsible SciComm”

1. In a similar vein, I don’t quite understand the comment “The key parameter is \rho, which is the proportion of the population that is at risk of severe disease, a fraction of whom will die (14%).” How certain is that last figure? What is the uncertainty in a given region? As I understand it, the fraction of infected people who die from the virus varies quite a bit from region to region and from country to country

• Anton Garrett Says:

I increasingly believe that that is due to differences in philosophy over cause of death. Many people die of opportunistic bacterial infection in the lungs, which attacks while one’s immune system is still recovering from battling this coronavirus.

• Phillip Helbig Says:

“I increasingly believe that that is due to differences in philosophy over cause of death. Many people die of opportunistic bacterial infection in the lungs, which attacks while one’s immune system is still recovering from battling this coronavirus.”

Divers say that if someone has a heart attack while diving it is a diving accident but if he has a heart attack while playing football then it is a heart attack.

On the other hand, death due to secondary causes presumably plays a role with respect to other viruses as well. (In fact, I think that AIDS itself is not dangerous, just the fact that one is then vulnerable to almost anything.) So it would be interesting to compare death rates from country to country for, say, normal influenza, aids, etc. (Of course, here as well the fraction of the population tested will also play a role.)

• Phillip Helbig Says:

“As I understand it, the fraction of infected people who die from the virus varies quite a bit from region to region and from country to country”

Of course, the more people who are tested, the lower the fraction who die. In a country where only those who are tested who have obvious symptoms, the fraction of those known to be infected who die will be much larger, because only a few are known to be infected.

2. Anton Garrett Says:

In Sweden, meanwhile, free association goes on (or nearly so). The exponentiating death rate will fall off very rapidly as soon as almost the entire population has had it, and Sweden is gambling that the proportion of very mild cases that never bother to see a doctor, plus totally asymptomatic cases, is very high; in that case the exponential will strangle itself down to zero without ever getting much worse than elsewhere. Quite a punt…

• Phillip Helbig Says:

As someone who has spent about a year in Sweden altogether, let me add some perspective. Sweden is different. It is larger than Germany but has about a tenth the population. Also, one thing one notices is that there are no old villages like in many European countries. This is due in part to the land reform carried out by Rutger Macklean back in the 18th century. In contrast to, say, Germany, where most farmers live in villages, in Sweden most farmers live on the land they farm. Part of the reason for this was to inhibit the spread of disease. Even though not many people are farmers these days, nevertheless there is much more personal space in Sweden than in most other places, probably at least in part due to this tradition. (It also had other consequences, such as Sweden being a leader in telecommunication while at the same time being in many respects a traditional society.)

Especially in the northern two thirds of Sweden, people are few and far between. As such, the policy isn’t as absurd as it might seem at first sight. However, it would certainly not be appropriate for a densely populated country.

Nevertheless, they have now closed their ski resorts, so current policy is different than what it was initially.

Whether their gamble will pay off is, of course, an open question.

Another thing to keep in mind is that, as long as there is neither vaccination nor effective treatment, travel restrictions and so on have the goal of slowing down the rate of infection to a level that hospitals can cope with it, not preventing it. How much restriction is required depends on how fast the virus would spread without them, obviously faster in more-densely populated countries, and also on the capacities of the hospitals.

• Anton Garrett Says:

Good grief, what a bastard Macklean was. I’ve just looked him up and his reforms. Reminds me of Ceausescu’s levelling of large numbers of traditional European villages. Thank you for mentioning this.

• Phillip Helbig Says:

I think that most people don’t see him as negatively as you do. In any case, sometimes bad actions can have good consequences.

• Anton Garrett Says:

Such as? The land reforms he put in place have been done elsewhere without the vandalistic levelling of half a nation’s vernacular architectural history.

• Phillip Helbig Says:

It does seem to have slowed the spread of disease. Again, bad actions can sometimes have good effects, which is not to say that they couldn’t be implemented in some other way.

• telescoper Says:

The current Covid-19 related death rate in Sweden is way higher than its Scandinavian neighbours.