At last we’re getting a debate about Covid-19 modelling. When people finally got to look under the hood of the famous Imperial College study, they found twisted and tangled code. And most of the model’s predictions bear little resemblance to what is actually happening. Some defend the models by saying that their predictions turned out to be wrong only because governments imposed harsher restrictions than the coders expected.
If so, we have a perfect experiment. Sweden did not close borders, shut down schools, businesses, restaurants, gyms or shopping centres and did not issue stay at home orders. So it should be the one country where the models fit. Let’s see.
Maria Gunther and Maria Westholm at Dagens Nyheter, Sweden’s biggest daily, just took a look at two of the most influential models in Sweden, both were inspired by the Imperial College study and published on the preprint server MedRxiv in April. Both were used by critics to argue that the Swedish model would quickly break our health care system – and that we had to make a U-turn into lockdown, as Britain did.
Here are the models’ prediction of the number of Covid-19 patients in Swedish intensive care units, ICU (the highest curve is a model without lockdown):
H. Sjödin et al: ‘Covid-19 health care demand and mortality in Sweden in response to non-pharmaceutical (NPIs) mitigation and suppression scenarios’, 7 April. The graph suggests critical care demand would peak above 16,000 patients per day by early May, and pre-pandemic intensive care unit capacity would be exceeded 30-fold.
Then came J. Gardner et al, ‘Intervention strategies against Covid-19 and their estimated impact on Swedish healthcare capacity’, 15 April.