Coronavirus statistical update: Numbers falling but R value needs to be reduced

While key parameters, including number of new cases and deaths, continue to show improvement, the reproduction rate, or R value, is not favourable for a move to a more relaxed alert level. Nick Terdre reports.

The government is now publishing the R figure, which represents the average rate at which a person infected with Covid-19 reproduces the virus by passing it on. On 22 May its range was estimated at 0.7-1. If the rate is 1, each infected person infects one other. So this estimate does not provide firm grounds for assuming that the number of infections is falling, which is a presupposition for reducing the alert level and introducing a further easing of restrictions.

When prime minister Boris Johnson spoke to the nation on 10 May, replacing the ‘stay at home’ slogan with ‘stay alert,’ he said that R stood at 0.5-09. So it has gone up since then. A five-stage alert level was introduced at that time –  we remain, where we began, at level 4, meaning that a Covid-19 epidemic is in course, with transmission high or rising exponentially.

The five alert levels introduced by the government – level 4 is currently in force.

In fact given that most of the parameters reported daily by the government indicate the spread of infection is being contained and the numbers affected reduced, level 3 would seem more appropriate – the defining characteristic of this level is that an epidemic is in general circulation, and prescribed actions are a gradual relaxing of restrictions and social distancing measures. On 21 May health minister Matt Hancock said that we are close to moving to level 3, but it seems that the R value will have to improve before such a move would be justified.

On 22 May 3,287 new cases were reported, bringing the total number to 254,195 (see main graph). The number of new cases was up by 672 on the previous day, but the numbers have been steadily falling since hitting a peak of 6,201 on 1 May.

East Sussex remains relatively lightly hit. Up to 22 May 675 cases had been confirmed, of which 50 were in Hastings, 88 in Rother and 148 in Eastbourne.

The number of tests reported recently passed three million. It now stands at 3,231,921 after 140,497 were reported on 22 May . As a person may be tested more than once for clinical reasons, the number of persons tested is less than these totals. The figures are also an aggregate of tests from which results are available and test kits sent out in the post. Using information supplied by the Department of Health and Social Care, HOT has calculated that on average test kits account for about one fifth of the total.

Hospital admissions in England are also falling. On 20 May 713 people were admitted to hospital. Peak admissions was 3,121 on 2 April. A daily figure for the number of patients under intensive care is not given, but the percentage of critical care unit beds occupied by Covid-19 patients on 21 May was 13% in England, 16% in Wales, 9% in Scotland and 5% in Northern Ireland. There is comfortably sufficient capacity to look after seriously ill patients in all parts of the country.

The number of Covid-19 patients in hospital is also in decline. On 21 May it totalled 9,307, down from 10,781 seven days before. The regional breakdown is as follows: East of England 740, London 1,018, Midlands 1,409, North-East and Yorkshire 1,067, North-West 1,517, Scotland 909, South-East 788, South-West 357, Wales 884 and Northern Ireland (20 May) 618.

On 22 May DHSC reported 351 deaths confirmed with a positive test in the UK, bringing the total to 36,393. The daily death toll peaked on 21 April with 1,172. It has since declined though with occasional spikes; the seven-day rolling average peaked at 943 on 14 April and on 22 May stood at 342.

The DHSC figures relate to deaths confirmed with a positive test. The figures compiled by the Office for National Statistics based on death registrations in which Covid-19 is mentioned on the death certificate, but not confirmed by a test, show a higher number. On 8 May the ONS reported 41,020  cumulative registered deaths from Covid-19 – the DHSC figure for the same day was 31,241.

The UK still stands second in overall death toll to the US, but a long way behind its total of 96,691 and more than 1.6 million confirmed cases as reported on 23 May by John Hoskins University.

Also in: Covid-19