Press Release: Study shows how risk of death rises with rate of overcrowding and corridor care in hospital emergency department
Embargo: 00.01 hrs CEST on Friday 25 September 2026
Paris, France: The risk of death for patients treated in the emergency department increases by one per cent for every ten per cent increase in occupancy, according to research that will be presented at the European Emergency Medicine Congress. [1]
The researchers say their findings show how overcrowding brings a very real risk for patients and provides evidence for policy makers and hospital managers on prioritising emergency care. Although the study was based on UK hospitals, the researchers say that given the levels of overcrowding in hospitals around the world their findings may apply in many other countries.
The research was presented by Dr Ryan McHenry from the University of Glasgow, UK, and an emergency medicine doctor in the West of Scotland. He said: “Emergency department overcrowding is an increasing public health concern internationally, with evidence that long delays increase patient mortality. Crowding is also associated with poor patient and staff experiences.
“There is less evidence around how crowding itself might be associated with mortality. Our traditional measures of emergency department crowding were developed in a time where crowding was less of an issue, and these simply aren’t sufficient to describe the crisis that currently exists in emergency care.”
The study included 19,034 patients being treated at 134 hospital emergency departments in Wales, Northern Ireland and England over five different time periods in 2025.
Researchers compared data on patient deaths within 28 days of being treated in the emergency department with information on occupancy on the day they were seen in the department.
Occupancy is calculated by how many spaces, such as cubicles, the department has compared with how many patients were being treated. For example, a hospital with 50 cubicles and 50 patients is at 100% occupancy, with 40 patients it is at 80% occupancy, and with 60 patients it is at 120% occupancy. The study showed that, on average, emergency departments were operating at 175% occupancy.
Analysis of the data showed that for every ten per cent increase in occupancy, the risk of dying from any cause within 28 days increased by one per cent. At the levels of crowding experienced by departments in this study, this equates to hundreds of deaths a week.
Dr McHenry and his colleagues also looked at the impact of ‘corridor care’ where patients receive treatment in non-standard clinical spaces such as corridors. This was also linked to an increase in the risk of deaths, in line with the risk associated with the occupancy rate. However, researchers say occupancy rate is much easier to measure and record.
Dr McHenry said: “We found that increased crowding in emergency departments is associated with increased mortality for patients admitted to hospital. This is important because we know that emergency departments are now often very crowded, and reducing that crowding has the real potential to save lives. Overcrowding is a problem in many countries and, although there will be regional differences, this link between overcrowding and patient deaths is likely to hold true around the world.
“A major strength of this study is its size and geographic reach, with participation from 139 emergency departments from across the UK. We’ve worked with hundreds of collaborators, collecting data that otherwise would be impossible to bring together. This gives us a detailed and accurate view of how crowding and corridor care impact patients.
“Extrapolating the results of this study across the UK means that emergency department crowding could have contributed to 554 deaths a week during the study period, as compared to a situation where departments had one space for every patient. Although we cover the majority of the emergency departments in the UK, this was still a relatively small study, and the possible range of expected deaths is therefore large; we estimate anywhere between 33 and 1,083 excess deaths are plausible. Regardless, these numbers track similar estimates of harm from long waits and crowding, and demonstrate the harms associated with the crisis in emergency care. Further studies are needed to confirm these findings and find a more precise estimate of the harms from crowding.
“We are already engaging with governments to ensure this research feeds into health service policy. We now need to find solutions that work in tackling emergency department crowding.”
The researchers have used their results to create a risk calculator (www.uncorkedcalculator.com) where emergency department staff can understand the risks for patients when their department is overcrowded.
Dr Felix Lorang is a member of the EUSEM abstract selection committee. He is head of the emergency department at Klinikum Lippe, North Rhine-Westphalia, Germany, and was not involved in the research. He said: “Around the world, the need for emergency care is growing, while infrastructure is failing to keep pace. Many emergency departments are operating far beyond capacity, and the ‘exit block’ — when patients are stuck in the emergency department because no inpatient ward beds are available — places an even greater burden on these emergency departments. This makes it harder for doctors and nurses to deliver the treatment patients need, or even the minimum treatment required to prevent further harm.
“This research makes it unmistakably clear to all of us — patients, medical professionals, and hospital managers alike — that overcrowding and corridor care mean many emergency patients will not survive.
“These findings can help hospitals understand the true impact of overcrowding in emergency departments. Understaffed and inadequately resourced emergency departments are, in themselves, an independent and dangerous health risk. But these results are especially critical for governments, politicians, and health services, because saving lives in emergency care is achievable — by preventing overcrowding, through sufficient staffing and through emergency departments that are adequately planned and equipped.”(ends)
[1] Abstract no: OA068, “The association between emergency department occupancy and mortality: a multi-centre prospective cohort study” by Ryan McHenry, Best abstracts session, Saturday 26 September, 11-12:30 hrs CEST, room 142.Funding: The UK Royal College of Emergency Medicine. The researchers also acknowledge all the time given voluntarily by collaborators across the UK to make this study possible.
