NHS bosses knew that a low roof at a Swindon mental health unit was a safety risk before a patient slipped off it 11 hours after scaling the building.

The woman, who suffered paranoia, needed emergency surgery after breaking her jaw, hip, pelvis and nose in the fall from the roof.

Avon and Wiltshire Mental Health Partnership NHS Trust has since apologised for the incident. In August, the trust was fined £80,000 by magistrates after bosses admitted failing to provide safe care at Sandalwood Court psychiatric hospital.

Now, an internal report on the incident has been published demonstrating AWP bosses knew the low roof was a risk. But it was agreed to manage that risk clinically, with ward staff assessing whether a patient was likely to abscond.

The authors of the report, released by AWP following a freedom of information request, said there was a systematic fault.

“The risk was on the health and safety register, it was highlighted annually and escalated trust-wide,” they wrote.

“It was agreed that the process of highlighting risk, escalating it, managing it and flagging up unresolved risks has been disjointed as the risk was on the health and safety register but the risk management did not move on from the clinical management to addressing the low roof line as such.”

The woman who fell had been admitted to the acute inpatient ward at Sandalwood on January 21, 2016.

She was said to have been particularly unsettled by an incident that involved the police. Other patients told her she would never leave the ward again. That heightened her sense of paranoia.

On the day after she was admitted to hospital she scaled the low roof from the hospital garden. The emergency services arrived by 6.50pm and despite the efforts of firefighters and a trained negotiator she refused to come down.

At 6.05am on January 23 she slopped from the roof of the acute inpatient ward. The incident was described as “catastrophic”.

In the damning internal report into the incident it was revealed that risk assessments had been cut-and-paste.

A matron said that “everyone cuts and pastes information” from a core document. But report writers concluded: “This cannot be accepted as completing a risk assessment.”

The record of the woman’s admission to the ward was said to be poor.

And the investigation found that when the person accompanying the female patient in the garden realised his companion was about to scale the roof he claimed to be unable to find a member of staff on the ward.

Since the incident, interim measures had been put in place to ensure patients were observed while they were in the garden. Every time a nurse hands over their patient to a colleague they would raise the risk of that patient absconding. And there was now an allocated “garden nurse” able to see into the green space.

AWP has apologised for the incident. Chief executive Dominic Hardisty said: “A patient suffered from harm whilst under our care and we offer them our sincere apologies for this. We let them and the NHS down, and have subsequently embarked upon a significant programme of changes to prevent something like this happening again.

“We are continuing to work with NHS England to ensure that funding is made available for further improvement works needed. In the mean-time we are carefully planning care and managing risk of harm on a patient-by-patient basis.”

Magistrates ordered AWP pay an £80,000 fine in August for safety breaches. The Care Quality Commission, which brought the prosecutions, said the roof fall was not an isolated incident.

Dr Paul Lelliott, deputy chief inspector of hospitals, said: “The trust had failed to make basic improvements to protect the people in its care despite having been aware of the dangers for years. They ignored clear evidence from their own reports on safety and as a result a patient suffered serious injury.”