Coronavirus: Too early to draw conclusions from hospital death rates, experts warn

·3-min read
LONDON, ENGLAND - MARCH 31: Paramedics deal with a patient outside St Thomas' Hospital on March 31, 2020 in London, England. British Prime Minister, Boris Johnson, announced strict lockdown measures urging people to stay at home and only leave the house for basic food shopping, exercise once a day and essential travel to and from work. The Coronavirus (COVID-19) pandemic has spread to many countries across the world, claiming over 40,000 lives and infecting hundreds of thousands more. (Photo by Ollie Millington/Getty Images)
It's too early to draw specific conclusions based on hospital death rates, experts have warned. (Picture: Ollie Millington/Getty Images)

It is too early to draw conclusions on coronavirus from official death rates, medical experts have warned, saying it may take up to a month for social distancing restrictions to have any visible effects.

According to the latest figures released by the Department of Health (DHSC), as of 5pm on Saturday the number of hospital deaths related to COVID-19 was up by 621 from the previous day.

That number is down from 708 deaths recorded on Friday and is the first time since March 29 that the number of deaths is lower than the previous day.

The figures come as Health Secretary Matt Hancock warned that the “small minority” of people breaking social distancing rules need to change their behaviour so lockdown restrictions can be lifted sooner.

But medical experts have warned that it is too early to draw specific conclusions based on death rates.

Professor Bharat Pankhania, senior clinical lecturer at the University of Exeter Medical School, said it was too early to say that death rates from coronavirus were on a “specific trajectory.”

He said: “The upward trend is still there on a daily basis; we can expect fluctuations – which this is.”

He said: “I would say it is too early for us to be able to say that the daily death rates from Covid-19 are on a specific trajectory. It’s too early to make any inferences from this.

“These sorts of variations are expected – in fact it would be suspicious if a trend was always in one direction without corrections and things to see – this is a normal pattern.”

Latest coronavirus news, updates and advice

Live: Follow all the latest updates from the UK and around the world

Fact-checker: The number of COVID-19 cases in your local area

6 charts and maps that explain how coronavirus is spreading

Prof Pankhania said it was too early to suggest that the number of cases was nearing a plateau.

“I would expect a rise in the number of cases to continue rather than for it to plateau and then tilt downwards,” he said.

Simon Clarke, associate professor in cellular microbiology at the University of Reading, welcomed the news of a smaller day-on-day increase but said it shouldn’t been viewed as evidence of a slowdown of deaths.

“It should always be remembered that these numbers do not include deaths in the community, so are a partial picture of the situation nationally,” he said.

“For similar reasons, we cannot know whether today’s jump in number of newly-diagnosed infections is significant. We will only know that we’ve reached the next phase, where the daily increase in numbers is expected to be plateau, after several days of consistent data.”

NHS staff gather ahead of the opening of the NHS of the NHS Nightingale Hospital at the ExCel centre, due to the spread of coronavirus disease (COVID-19), in London, Britain April 3, 2020.  Stefan Rousseau/Pool via REUTERS
Latest official coronavirus death figures don't necessarily include deaths in the community, experts have warned. (Picture: Stefan Rousseau/Pool via REUTERS)

Experts have also warned that it is too early to see the effects of social distancing due to an “inevitable delay” in recording data.

Peter Openshaw, professor of experimental medicine, Imperial College London, said: “Deaths typically occur almost three weeks after the onset of disease, which is usually about five days after exposure to the virus.

“Reduction in deaths would not be expected until about a month after measures are put in place.

He said: “The present measures aim to confine disease to within households, and secondary cases within households are bound to take time to feed through into the statistics.

“Given this inevitable delay, there are some early signs that the measures already taken are having some effect.”

Prof Openshaw did not rule out the possibility of stricter measures being introduced, but added that the main problem currently was that some people were not being “fully observant” of those already imposed by the Government.

Coronavirus: what happened today

Click here to sign up to the latest news, advice and information with our daily Catch-up newsletter