Is NHS 111 making Emergency Department overcrowding worse?

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By Michael Marshall

As 'corridor care' becomes routine in hospitals across the UK, Doctors.net.uk examines whether the telephone triage service is truly part of the problem, as many emergency medics fear.

In hospitals across the UK, emergency patients are being treated in hallways and other unsafe places. This “corridor care” crisis is harming both patients and healthcare professionals: the Royal College of Nursing quoted one nurse saying that corridor care amounted to “a type of torture” for patients, while emergency medics have been left distraught as they scrabble to cope with unprecedented levels of demand.

Some emergency departments are seeing more than 150 extra patients each day than they were designed to accommodate, and even as more and more departments have resorted to declaring critical incidents, they question whether such measures make any real difference.

Amid this worsening crisis, many NHS staff have expressed concern that the NHS 111 service may be part of the problem, making matters worse by sending too many people to emergency departments. We look to the evidence to see what is actually ramping up the pressure on emergency departments – and what role 111 really plays.

Unsuitable spaces

For a start, the facts on the corridor crisis are stark. In February 2025, a survey by the Royal College of Physicians showed that almost four in five doctors had provided care in an “unsuitable space” in the previous month, including corridors, waiting rooms and even bathrooms.

In the summer of 2025, one in five emergency department patients were treated in trolleys or chairs, according to the Royal College of Emergency Medicine. What’s more, enormous numbers of patients faced unacceptable waits for this treatment. Between July and September, more than 116,000 patients waited more than 12 hours in an emergency department, according to the Royal College of Nursing.

There is an awful lot more demand – and more complex demand – on all NHS services

To some extent, this reflects wider pressures on the NHS. “Demand has been going up, and it’s been going up for everything,” says Professor Catherine Pope, a medical sociologist at the University of Oxford. Inequalities mean poorer people and people from more deprived areas are sicker, often with multiple chronic conditions. The UK also has an ageing population. “Those things are a perfect storm that just mean there’s an awful lot more demand, and more complex demand, on all our services.”

So how does NHS 111, which refers many patients to emergency departments, factor into all of this?

A gigantic flowchart

When it was launched in the early 2010s, and rolled out nationally in 2013, 111 was supposed to send patients to the appropriate care, ultimately easing pressure on emergency departments. Yet in the following decade that pressure has only intensified.

The 24-hour helpline is intended to guide patients to the correct service. People experiencing a life-threatening emergency should still call 999; 111 is for non-life-threatening but “urgent” needs. An online counterpart, 111 Online, was launched in 2017.

The phone line and website are both based on a piece of clinical decision support software called NHS Pathways. This is essentially a gigantic flowchart: patients are presented with a question and depending how they answer they are given different follow-up queries, until the system finally arrives at a decision, or “disposition”. This can be anything from “just take a paracetamol and sleep it off” to “actually, this is an emergency, we’re calling an ambulance”.

On the helpline, trained operators guide callers through the questions. This reliance on non-clinical staff is a shift from the previous service, NHS Direct, which was staffed by nurses. Nevertheless, Pope says the operators are “really good” at translating the questions for people who may have limited comprehension and often work together to solve tricky problems.

On the website, there is only the patient filling in the questions and the ingenuity of the designers. “It’s used by a layperson, and it’s often used when they’re not well,” says Pope. The designers had to take those limitations into account.

Given this, NHS 111 gives patients appropriate advice most of the time. In a study published in July 2025, expert clinicians reviewed 189 cases from NHS 111 Wales, and generally agreed with the decisions made. Where the clinicians were in consensus, they agreed with NHS 111 Wales’ decisions 90.5% of the time. Likewise, a 2024 study of NHS 111 calls found that they were successful at encouraging patients who needed to attend the emergency department to do so.

What NHS 111 hasn’t done is create a drop in demand for emergency departments. “It doesn’t appear to have reduced demand significantly,” says health services researcher Professor Fiona Sampson at the University of Sheffield in the UK.

Almost 20% of 111 callers are sent to the emergency department

Before 111 was launched more than a decade ago, many emergency department staff expressed concerns about the way it would impact demand – and this scepticism remains.

For research published in 2023, Pope and her colleagues interviewed 27 ED staff. Unsurprisingly, they said that the system’s assessments were less robust than those conducted in-person. “They feel that they can use their clinical expertise, and they’re a bit worried that the call handling process isn’t expert enough,” says Pope.

When Pope and her colleagues assessed the initial rollout for a 2016 study, they found that 11.3% of calls led to an emergency ambulance being dispatched, while a further 8.1% were advised to attend the emergency department. This means almost 20% of callers were sent to the emergency department. “When I talk to emergency department doctors, they feel that those rates are too high,” says Pope.

However, it’s precisely the limitations of telephone and online assessment that mean 111 is designed to err on the side of caution. “I think I can say that there is over-referral to emergency departments and probably too many ambulances, but that’s part of what makes it safe,” says Pope. “What you don’t want is that one baby that had a rash [that] turned out to be meningitis, or that one person that had a combination of symptoms that turned out to be sepsis.” Indeed, in August 2025 a coroner criticised 111’s algorithm after it failed to detect a case of sepsis, leading to a baby dying.

To avoid cases like this, 111 operators are generally risk-averse. A study published in February 2025 assessed more than 98,000 callers that went through NHS 111, and who were subsequently seen by clinicians: it found that operators preferred to send patients to emergency departments when they were unsure.

Sampson adds that emergency department staff don’t encounter the non-urgent patients that NHS 111 successfully diverts: the mistake that is most visible to them is over-referral.

What counts as an emergency?

The evidence about clinically unnecessary attendance at emergency departments is messy. There are at least three groups of people: those who need clinical attention but could be seen elsewhere; those who only need to be in the emergency department because they didn’t get care elsewhere; and those who don’t need clinical attention at all, but might need something else, such as social care.

A 2010 study – prior to the introduction of NHS 111 – surveyed people who attended the emergency department despite having a non-urgent condition. The majority did so because they incorrectly believed their condition was urgent. This suggests a need to improve health literacy. However, a 2022 review found that the evidence base for health literacy interventions was “inconsistent”.

More recently, a study called Drivers of Demand for Emergency and Urgent CarE (DEUCE) interviewed people to find out why they went to the emergency department. The team identified many factors, including the need for relief from intolerable pain, feeling responsible for a child’s health, and difficulty getting timely access to primary care. Those with “complex and stressful lives” were particularly prone to go to the emergency department, because they knew they could get seen. Likewise, people with lower skilled or manual jobs were more likely to call an ambulance for non-urgent conditions – while young adults were often concerned about the impacts of ongoing symptoms on work and study.

Even if NHS 111 is contributing to overcrowding in emergency departments, a much bigger factor is people struggling to get care elsewhere. “Patients are bouncing around between services, and they’re losing faith,” says Sampson. “Primary care is a massive issue.” People who can’t see their GP or other primary carer will resort to the emergency department because it’s always open and they know they will be seen.

In line with this, a 2024 study of NHS 111 calls in Yorkshire found that about 48% of callers are advised to contact primary care, but fewer than half of them manage to do so, and it often took longer than the timeframe advised by NHS 111. The authors concluded that "current primary care provision cannot meet the demand from 111".

While NHS 111 isn’t easing the strain on emergency departments, it also isn’t the root of the corridor care crisis.

Sampson says overcrowding in emergency departments is also a downstream effect of overcrowding elsewhere in hospitals. The real danger, she says, is “the people who are really sick and need looking after but can’t be admitted because the hospital’s full.” This is due to lack of beds and difficulties with discharging people to be cared for in the community or by GPs.

In short, the reality of NHS 111 is nuanced. Researchers conclude that it probably does over-refer patients to emergency departments, but that is almost unavoidable for safety reasons. However, the confusing array of non-emergency treatment centres is likely to be a bigger factor. So is a lack of beds in hospitals to which inpatients can be discharged – not to mention the ongoing shortage of GPs, which prevents primary care from picking up referrals from NHS 111. The fact is that while NHS 111 isn’t easing the strain on emergency departments, it also isn’t the root of the corridor care crisis.

“People navigate to the emergency department because it’s the one constant in a system that’s constantly changing, and because we’ve got some serious problems with access to general practice at the moment,” says Pope.

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