The nation’s top doctor has described how he was “terrified” the NHS was going to be overwhelmed as officials drew up an unpublished document describing who should be prioritised for care if the service exceeded capacity in the early stages of the Covid-19 pandemic.

The document was never officially released as it became clear that the nation was reaching the peak of the crisis, NHS England’s national medical director said.

Professor Sir Stephen Powis told the UK Covid-19 Public Inquiry that the work was something that “nobody ever wants to do”.

The “prioritisation” document was written in March 2020 to be considered should the NHS become overwhelmed with Covid-19 cases.

The inquiry was shown the unpublished document, titled Covid-19 Decision Tool, which highlights three elements to consider when prioritising care: age; “clinical frailty” and “comorbidities”.

Patients were given “points” based on their age, with under 50s placed at zero and 80-year-olds starting at six points.

It also ranked patients from one to nine, one being fit and well and nine being terminally ill, while co-morbidities such as previous heart attacks, high blood pressure and heart failure also scored with points.

A point was taken off for women.

The scores would then dictate what sort of care should be provided to the patient.

Frankly, I was personally terrified, terrified that the NHS was going to be overwhelmed and doctors were going to be placed in a position, and other clinicians, where they would not be able to make the professional judgment that they usually make in terms of treatments and escalation

Sir Stephen said: “In terms of this decision tool, which was never authorised, it was never officially released.

“It didn’t go beyond this stage other than the group that developed it subsequently published a version of it in an Intensive Care Society set of principles around decision-making.”

The inquiry heard that the “impetus” for the document came from the Department of Health and Social Care but on March 28 a decision was made that it should not go ahead.

Sir Stephen continued: “This was at a point in March where cases of Covid were rapidly increasing.

“The strategy that the NHS and government had taken was, on the one hand, to put in social distancing, in other words lockdown, to reduce the rate of transmission, and within the NHS our job was to surge capacity.

It was not clear whether the public would respond to lockdown - they did wonderfully, but that was not clear

“But at that point in March, the number of patients with Covid in ITU (intensive care) beds was doubling every five to seven days.

“We couldn’t see – because there was no community testing at the time – what was likely to come ahead.

“It was not clear whether the public would respond to lockdown – they did wonderfully, but that was not clear.

“Frankly, I was personally terrified, terrified that the NHS was going to be overwhelmed and doctors were going to be placed in a position, and other clinicians, where they would not be able to make the professional judgment that they usually make in terms of treatments and escalation.

“And in those circumstances, I and my clinical colleagues and CMOs (chief medical officers), felt that we should begin to explore a decision tool such as this.”

He added: “It was halted, I think because a number of us, the Chief Medical Officer, myself, with input from the (then) chief executive of NHS England, came to the conclusion that it should not be released.

“For me, the main reason was at this point, it was becoming increasingly clear to me that the peak of the pandemic was approaching and, therefore, it would not be needed, because we would not breach capacity.”

There was also a “danger” that the tool would have taken away some professional judgment made by doctors and could have been seen as “too simplistic”.

“I think it was right to stand it down because we didn’t need it and it could have been used inappropriately,” he said.

Sir Stephen also said he shared a concern that the document would be controversial and risk a poor reaction from the public.

He suggested that capital investment in the NHS estate will give the health service more resilience against future pandemics.

Sir Stephen told the inquiry some buildings were so old that there was difficulty piping in oxygen during the crisis.

“Clearly, much of the estate in the NHS in England is much older than it needs to be, and that has a whole host of consequences,” he said.

“We haven’t talked about it, but I know you have heard how we had difficulty piping oxygen through to the older estate, where the piping simply couldn’t take the volumes of oxygen going through it.”

He said some people may have misinterpreted public health messaging during the crisis.

He told the inquiry: “The ‘protect the NHS’ message, which was a Cabinet Office-developed communication strategy, I think was the best intent.

“It was to recognise that people were sacrificing, great sacrifices, in terms of social distancing and lockdown, to ensure the transmission rates dropped and that relieved pressure on the NHS, and, of course, reduced deaths.

“But of course, unfortunately, some people might have interpreted that as ‘stay away from the NHS’, which was absolutely not what we wanted. We were quite clear that if you had a condition that required NHS treatment, you should come forward.”

Sir Stephen became emotional when he recalled how his words helped “save” a person’s life.

We have heard of terrible hardship and loneliness, but also true commitment and sometimes even bravery

He said he raised the issue about people potentially not seeking care “at a very early stage” of the pandemic during a Downing Street press conference in early April.

“I remember getting an email from somebody afterwards saying ‘my husband, we’ve been sitting at home for a number of days, with the chest pain’, I think it was, ‘and wouldn’t go to hospital. They heard you on the television, and he went, and they saved his life’,” he said.

“And so I think it had an impact.”

It comes as the inquiry’s Every Story Matters campaign hit the 50,000 submission milestone.

The public engagement exercise is aiming to better understand the public’s pandemic experiences and will shape the probes recommendations.

Ben Connah, secretary to the Covid-19 inquiry, said: “We have heard of terrible hardship and loneliness, but also true commitment and sometimes even bravery.”