Covid-19 Rates for local areas, taking population size into consideration

I got fed up with raw rates such as those given in the Guardian. For one thing, how can you compare the number of people infected in an area with nearly 1.4M (Hampshire) with the number in an area with less than 100K (Hartlepool). It simply does not make sense.

One way to correct this is to divide by the population size which I got from the government projections for 2020. Unfortunately the data, I found, only contained the figures for England. I took the rate per 10k of the population for diagnosis. The choice of per 10k of the population in a local area was made because of the number of positive tests at present if minuscule compared with the total population. It is a measure of population penetration of Covid 19. What I am going to produce below is a graph of the top quintile of local areas measured by the number of positive tests for Covid-19 per 10K of population

The average for London is 4.4 people diagnosed per 10K in the population, but that is heavily influenced by the high rates in Wandsworth, Westminster, Harrow, Brent, Kensington and Chelsea, Lambeth and Southwark. The median London Borough local area is Islington with 3.9. The rates per 10k for places outside London high : Sheffield (4.1), Wolverhampton (3.9) and Cumbria (3.5).

Now a warning. The positive tests are actually a pretty poor measure of population penetration. We are at present only really testing the very sick who need to come into hospital. This leaves a huge number with symptoms from a mild cough through to severe flu symptoms who are not being tested. If you then add in that Iceland found about 50% of positives had no symptoms then we are not really testing in any pattern that would pick up actual penetration. What is more, the rules for testing, I suspect, differ Health Authority to Health Authority and hospital to hospital, maybe even doctor to doctor.

There is a high rate of Coronavirus infection in seven London Boroughs out of 31 I could identify in the list. However when you compare infection rates over the whole of London you find that there are a few other places apart from London that seem to have a comparable list.

A side note: will all those who went to the Lake District last weekend please note how high it is on the list. You’d have been less likely to get Covid-19 if you had stayed at home.

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