On Saturday 31st October, the UK truly had a Halloween fright when it was announced that England would be put back into lockdown from 5th November (the rest of the UK is in various states of lockdown already).
The Reproduction number, R, is a key estimate driving such decisions. R is the average number of people infected by one infected person (estimate remember). If R is greater than 1 the epidemic is growing, if R is less than 1 the epidemic is shrinking.
If R is so important, it makes sense to examine how closely it is associated with deaths.
In the image below, I have taken deaths with Covid-19 for England & Wales (Ref 1), Scotland (Ref 2) and Northern Ireland (Ref 3) and added them together for UK deaths.
This government site states that the R number was first reported on 15th May 2020 (Ref 4). The site reports subsequent R estimates. I obtained a couple of estimates of R earlier than 15th May from the slides presented by Whitty and Valance – the leaders of SAGE – from the 31st October national briefing (Ref 5).
I have plotted on the same graph:
1) Deaths for the UK with Covid-19 from week 11 until week 42 – the most recent data for the whole of the UK. This is plotted on the left hand Y axis.
2) The R estimate when known during this period. R is presented as an estimated range with a high point and a low point, so the red lines show the estimated range. This is plotted on the right hand Y axis and I have added a black line to show the R = 1 point. R is currently falling and I will update this as more data become available.
I’ll leave it to you to see if you think there’s a strong relationship between the R estimate and UK deaths with Covid-19.
Ref 1: https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/deaths/bulletins/deathsregisteredweeklyinenglandandwalesprovisional/weekending16october2020
Ref 2: https://www.nrscotland.gov.uk/covid19stats
Ref 3: https://www.nisra.gov.uk/publications/weekly-deaths
Ref 4: https://www.gov.uk/guidance/the-r-number-in-the-uk#history
Ref 5: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/931775/Slides_to_accompany_coronavirus_press_conference-_CSA-__31_October_2020.pdf