Health Secretary Matt Hancock has ordered an urgent review into how Public Health England (PHE) calculates daily Covid-19 death figures.

It comes after researchers criticised “statistical flaws” in the way the deaths are reported across England, saying they are left looking far worse than any other part of the UK.

PHE’s figures feed into the daily death statistics published by the Department for Health and Social Care (DHSC).

Data from Public Health Wales, Health Protection Scotland and the Northern Ireland Public Health Agency is also fed in.

The daily DHSC data represents the number of reported deaths of people who have tested positive for Covid-19, who have died in all settings.

But in a blog entitled “Why no-one can ever recover from Covid-19 in England – a statistical anomaly”, Professors Yoon Loke, from the University of East Anglia, and Carl Heneghan, from the University of Oxford, said more robust data is needed.

They argued that PHE looks at whether a person has ever tested positive and whether they are still alive at a later date.

This means anyone who has ever tested positive for Covid-19 and then dies is included in the death figures, even if they have died from something else.

“PHE does not appear to consider how long ago the Covid test result was, nor whether the person has been successfully treated in hospital and discharged to the community,” they said.

“Anyone who has tested Covid positive but subsequently died at a later date of any cause will be included on the PHE Covid death figures.

“By this PHE definition, no-one with Covid in England is allowed to ever recover from their illness.

“A patient who has tested positive, but successfully treated and discharged from hospital, will still be counted as a Covid death even if they had a heart attack or were run over by a bus three months later.”

The experts said this is the reason why PHE figures “vary substantially from day to day”.

They also said that about 80,000 recovered patients in the community are continuing to be monitored by PHE for the daily death statistics, even though many are elderly and may die of something else.

They concluded: “It’s time to fix this statistical flaw that leads to an over-exaggeration of Covid-associated deaths.

“One reasonable approach would be to define community Covid-related deaths as those that occurred within 21 days of a Covid positive test result.

“In summary, PHE’s definition of the daily death figures means that everyone who has ever had Covid at any time must die with Covid too.

“So, the Covid death toll in Britain up to July 2020 will eventually exceed 290k, if the follow-up of every test-positive patient is of long enough duration.”

The experts said the issue relates to England because Scotland and Northern Ireland use a 28-day cut-off.

On the Government death statistics website for England, the issue is acknowledged, saying: “Deaths are counted where a lab-confirmed positive coronavirus test result is reported in any setting.

“This means that not all deaths reported here are caused by coronavirus.”

Other data on deaths, regarded by many experts as more reliable, is put out by the Office for National Statistics (ONS).

PHE said it could not be ruled out that Covid-19 was a contributory factor in some deaths.

Dr Susan Hopkins, PHE’s incident director, said: “Although it may seem straightforward, there is no World Health Organisation agreed method of counting deaths from Covid-19.

“In England, we count all those that have died who had a positive Covid-19 test at any point, to ensure our data is as complete as possible.

“We must remember that this is a new and emerging infection and there is increasing evidence of long-term health problems for some of those affected.

“Whilst this knowledge is growing, now is the right time to review how deaths are calculated.”

Christina Pagel, a mathematician and professor of operational research at University College London (UCL) and a member of the Independent Sage group, said the way PHE calculates data could become an issue as time goes on but she did not believe there had been a “massive distortion”.

She added: “For Matt Hancock to suddenly be launching a massive inquiry is odd.

“The Department of Health website says quite clearly how each country is doing its death calculations, so it shouldn’t be a surprise to him. That’s what I find really odd.”