Mental health patients are sometimes forced to spend “days” in the Whittington’s A&E department waiting for a bed, a new report has revealed.

An independent review into mental health care at the Archway hospital was carried out following the deaths of seven patients between November 2014 and December 2016 – the last five of which all came in the space of three months.

The investigation found although there was no single issue with the level of care, the demand for the service, waiting times and the “environment” of the A&E contributed to the deaths.

It said: “Bed availability is the major factor in very long delays for mental health patients as the length of time it takes to find a bed leads to them having to spend many hours, and sometimes days, in the department.”

The patients all died after hospital visits. Not all were ruled suicides, but inquests found they were all linked to apparent acts of self-harm. One of the patients was Crouch End security guard Dominic White, 27, who had bipolar affective disorder and psychosis.

In November 2016, after being given leave, he walked out of A&E before he could be moved to a specialist mental health unit. His body was found the next day.

Following Mr White’s death, senior coroner Mary Hassell issued a prevention of future deaths report (PFDR) amid concerns over monitoring of A&E patients at the Whittington and said allowing him leave after he had been sectioned was “very unusual”.

Her PFDR was one of 271 coroners issued to NHS bodies following mental health patient deaths between 2012 and 2017 – 45 of which were, The Guardian revealed in March, regarding lack of beds, staff and specialist services.

Initially, Whittington Health NHS Trust, Camden and Islington Mental Health Trust and Barnet and Enfield Mental Health Trust carried out serious incident reports.

But after finding no overarching factor causing the deaths, consultancy firm Verita was hired to carry out another, independent, review.

The report, published last month, found the number of mental health patients visiting A&E had increased in recent years due to “wider societal issues”, causing delays and longer waiting times.

It added: “Emergency departments are generally not good places for people with mental health problems who would ideally be seen in calm, quiet environments.”

The environment at the Whittington was found to be “very poor”, though the trust has plans to improve it.

Verita said long waits are “likely to continue” and the trusts should ensure facilities are “as fit for purpose as possible”. It said “compelling evidence” showed practice at the hospital had improved “greatly” since the deaths.

A spokeswoman for Whittington Health said: “Mental health patients who have such long waits in our emergency department are those who need a specialist mental health bed provided by another organisation.

“We are committed to keeping patients safe while they wait with us – this is why we have recently renovated our facilities for sectioned patients and will open a new suite staffed by Camden and Islington Mental Health Trust.”