1. Some people are looking at today's Public Health England report and concluding the Case Fatality Rate for Delta positive cases is 6.5 times higher for vaccinated compared to unvaccinated. But this is an instance of Simpson's paradox as shown by this table 
2. Colleague .@MartinNeil9 pointed this out. In both age categories the rate among vaccinated is lower but when aggregated vaccinated is higher. It's because a much greater proportion in the older group are vaccinated compared younger group & most deaths occur in the former
3. It's worth noting, however, that in the <50 age group there's little difference in fatality rate between vaccinated & unvaccinated. Also, worth noting the concerns I've raised generally about all studies into risk/benefits of Covid-19 vaccines here: probabilityandlaw.blogspot.com/2021/06/why-al…
4. For a short video explaining Simpson's paradox, see:
5. And a more complex example is here:
6. Finally, for those who’ve interpreted this thread as an argument in favour of the vaccine: it’s not. I don’t think a convincing case of benefits over risks has been made, especially for the under 50s. But it’s important to call out stats errors on ‘both sides’ of the argument
7. Oops here is the correct table with the aggregated deaths:
8. Also important to note that the data that is completely missing is that relating to deaths (or serious adverse reactions) of vaccinated v unvaccinated people who were NOT classified as having COVID. So no information on vaccine risks
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