Dr Elizabeth Webb recently wrote about R, the number we’ve been hearing so much about, and why it’s important to keep it below 1. This week she discusses how R is estimated, and what can be done to keep it low.
While, in theory, R is a precise figure, it can be difficult to pin down. R can change over time, as the amount of social contacts we all have changes, and as the number of people who have had coronavirus increases. R can also differ between settings and between geographical areas.
To know exactly what R is, we would have to find out how many people every person with coronavirus passed it to, and work out the average number from that. At the height of an epidemic this is very difficult to do, and the moment it isn’t possible in the UK. As we don’t have this information, how is R being estimated?