Continuous flow model: Does it work and is it safe?

The shocking case of a 39-year-old woman who died on January 22, days after being found lying unconscious under her coat in a Nottingham A&E, has highlighted once again the danger of avoidable tragedies in overcrowded emergency departments.

The patient had reportedly attended complaining of a severe headache but had been waited seven hours without being seen by a doctor.

An investigation is underway, but it begs the question: what can, and is, being done to address the gridlock engulfing A&E departments which - UK-wide - has become so much worse over the past five years.

One strategy is the "continuous flow" model. Yet, as emails leaked to the Herald show, it comes with its own controversy.

‘Spreading the risk’

In December 2022, NHS Greater Glasgow and Clyde introduced its 'GlasFlow' model at the Queen Elizabeth University Hospital.

The basic idea - now in place across all its adult hospitals - is that a fixed number of patients requiring admission are continuously transferred at certain times each day from A&E onto wards, regardless of whether a bed is available.

This can mean that patients lie on a trolley in a side room or get 'doubled up', with two beds in a single-person bay.

Obviously it also means that the nurses and doctors in that unit - which may already be short-staffed - might end up caring for 50 patients in a department supposed to accommodate a maximum of 40.

Clearly this is not ideal, but the argument goes that it enables hospitals to "spread the risk" of overcrowding more evenly instead of leaving A&E departments to bear the brunt alone.

Prolonged stays in A&E are strongly associated with excess mortality, and the main reason patients spend 12 hours or more in emergency departments is because they are waiting for a bed on a ward.

Moving patients onto wards more quickly also frees up space so that patients lying in ambulances at the front door can be brought into A&E.

The continuous flow concept originated North America but is better known in the UK as the 'North Bristol' model after the NHS trust began piloting it there in mid-2022, resulting in significant improvements in its A&E waiting times performance.

In Scotland, Ninewells hospital in Dundee - where waits of over eight and 12 hours remain rare - also has a well-established a flow model.

Read more:

• Row over Glasgow superhospital 'continuous flow' model
• Swamped A&E departments 'like playing Russian roulette', say medics 
• What do Scotland's rising heart attack death rates tell us about hospital overcrowding?
• NHS in crisis: Is the health service as we know it over? 

Does it work - and is it safe?

In the year since the QEUH introduced GlasFlow, there has been a small improvement in the percentage of patients spending over 12 hours in its ED - from 7.5% in December 2022 to 5% in December 2023, and a spokesman for NHS GGC said it has also led to a "reduction in the overall length of stay in our A&Es".

However, nearly one in five (18%) were there for over eight hours and the QEUH also recorded its worst ever performance against the four-hour target in the first week of January, so it is clearly no panacea.

Meanwhile, staff have voiced concerns over safety.

Internal emails from August and September last year, recently shared with the Herald, show consultants escalating concerns to management.

This includes a complaint from a patient who had to sit in a day room for five hours waiting for a bed and warnings that there had been a "progressive deviation" from agreed protocols in the months since GlasFlow was introduced.

Number of patients attending A&E at Queen Elizabeth University Hospital in Glasgow who have spent over four, eight, and 12 hours there prior to being discharged, admitted, or transferred to another hospital - January 2008 to present (Image: PHS)

In particular, they said that "unstable" patients - those requiring respiratory support, suffering acute heart attacks, potentially infectious acute Covid patients, and people with severe anaemia - were "regularly being moved to ward corridors or non-clinical rooms".

"Basic patient safety, dignity and care requirements are not being supported," they added, before going on to caution against "further suggested changes" said to include moving patients out of rooms into corridor care prior to discharge to free up beds, or transferring patients to other clinical areas (for example, moving a patient recovering from cancer surgery onto an orthopaedic ward to make space for a new admission onto the oncology ward).

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                                                                                                                                                                      One email encouraged colleagues to "record all adverse patient instances related to [continuous flow model] in Datix" - the risk management system used by NHS Scotland.

A spokesman for NHS GGC said: "The protocols for [GlasFLOW] make clear that certain patients must be admitted directly into a bed for safety and/or dignity and privacy reasons.

"Where there are occasions that the protocols have not been followed, these are reviewed via our governance arrangements.

"We have also met with staff to hear and address any concerns about the approach.

"Whilst we recognise that GlasFLOW is not the complete answer to urgent care, it is an important component of our urgent care pathways that is helping tackle overcrowding at our front doors."

To date, there has been no formal independent evaluation anywhere in the UK to assess the safety of flow models despite their increased rollout.

Until there is, it is impossible to say whether this remedy for A&E overcrowding is reducing mortality overall - or just exporting the problem to other parts of the hospital.