A very interesting article was recently published in Lancet that sought to understand which factors correlate, on a country level, with covid related outcomes. The study was observational, so it can only show correlation, not causation, but it can still give pretty strong hints as to which factors protect people from covid, and which factors increase the risk of being harmed.
One of the most frequent questions I’ve been getting recently is how accurate I think the covid tests are, and in particular the PCR tests. As it happens, a systematic review has recently been published in Evidence Based Medicine that looks at the covid tests (both PCR and antibody), so I thought it would be interesting to look in to the evidence together. This article gets a bit technical and math-heavy in places, so please bear with me. I think the payoff is worth it.
The Swedish response to the covid pandemic has become one of the most talked about topics of the last six months, and there’s a lot of misinformation floating around. Since that’s the case, and since I keep getting asked what the situation on the ground is really like in Sweden, I figured I’d write up a little history, covering the key events from a Swedish perspective, and detailing exactly which restrictions were put in place at what time point, and why.
This is a guest post written by a colleague who works as a care home doctor in a small Swedish town. In other words, he is responsible for the wellbeing of frail elderly people living in care homes. He has treated a lot of patients with covid-19. Since the situation may be different in some other countries, I think it is useful to know before reading the article that in Sweden, people stay in their own homes until they are very close to the end of their lives. 50% of people who move in to care homes are dead within six months.
September 2020 was the least deadly month in Swedish history, in terms of number of deaths per 100,000 population. Ever. And I don’t mean the least deadly September, I mean the least deadly month. Ever. To me, this is pretty clear evidence of two things. First, that covid is not a very deadly disease. And second, that Sweden has herd immunity.
UPDATE 14th November 2020: In light of the recent increase in hospitalizations and deaths during October and November in Sweden, I no longer believe that Sweden reached a state of herd immunity during spring. The text below represents my thinking on the 19th of September, when I wrote the article, and doesn’t represent my current thinking. It is clear that a significant level of population immunity did build up during spring and summer, since the rise in hospitalizations has been much slower during the autumn than it was during the spring, and also seems to be stabilizing at a much lower level. However, the level of population immunity is clearly not as high as I previously thought. The reason I made this mistake is that the early evidence on covid suggested that it was not behaving in a seasonal manner. This caused me to underestimate the seasonal effect of summer to push down infections, which caused me to overestimate the level of population immunity that had built up during spring. It is now clear that covid is a highly seasonal virus.