Is the British Covid Variant Really ‘Twice as Deadly’?
There follows a guest post from HART member and Lockdown Sceptics veteran Dr Clare Craig responding to the alarming reports today that, as the Express headline put it, “Kent Covid strain could be twice as deadly”.
Yesterday the BMJ published a new article comparing mortality rates in people with old variant Covid and new variant Covid from October through to the end of January. Their headline conclusion was that the risk of dying was 64% higher in people who had caught the new variant (and perhaps up to 104%, hence the headline that it “could be twice as deadly”).
Before worrying that this may be the case it is worth looking closer at their results. There are a number of odd things about this study:
- Each person with old Covid was matched for sex, age, ethnicity, deprivation, location and date of infection. There were over 214,000 pairs found. However, it turned out that there was extensive duplication in the data and many of these “cases” were the same people. After removing duplicates there were only 54,906 pairs left.
- The two groups were not matched for comorbidities, meaning the study did not control for them. This was unfortunate as many comorbidities increase the mortality rate significantly.
- Their main finding was that 227 people in the new variant group died compared with 141 in the old variant group. This equates to a 99.59% survival rate compared to a 99.74% survival rate. While the difference may – according to the authors’ methodology – have been statistically significant, this does not equate to it being of any practical relevance in terms of the threat of this virus to society.
Is the British Covid Variant Really ‘Twice as Deadly’?Read More