Death Risk Climbs Steadily as Hospital Emergency Departments Fill Beyond Capacity

Every ten per cent rise in the occupancy of a hospital emergency department increases a patient’s risk of death within 28 days by one per cent, according to a large observational study presented at the European Emergency Medicine Congress in Paris. The research, led by Dr Ryan McHenry of the University of Glasgow and an emergency medicine doctor in the West of Scotland, drew on data from more than 19,000 patients treated at 134 emergency departments across England, Wales and Northern Ireland during five separate time periods in 2025. Its central finding is stark: crowding is not merely an inconvenience or a sign of strained logistics, but a measurable hazard that appears to cost lives on a scale reaching into the hundreds each week.

The study compared records of patient deaths within 28 days of emergency department attendance with information on how full the department was on the day each patient was seen. Occupancy was calculated in a straightforward way: by dividing the number of patients being treated by the number of available treatment spaces such as cubicles. A department with 50 cubicles and 50 patients operates at 100 per cent occupancy; with 40 patients it sits at 80 per cent, and with 60 patients it is at 120 per cent. By this measure, the departments in the study were operating at an average of 175 per cent occupancy, meaning that on a typical day many patients were being treated in spaces never designed for clinical care.

Analysis of the data showed that for every ten per cent increase in occupancy, the risk of dying from any cause within 28 days rose by one per cent. When the researchers extrapolated this relationship across the United Kingdom, they estimated that emergency department crowding could have contributed to 554 deaths a week during the study period, compared with a hypothetical situation in which every department had one space for every patient. Because the study covered the majority but not all of UK emergency departments and was, as the authors acknowledge, relatively small in statistical terms, the plausible range of excess deaths is wide: anywhere between 33 and 1,083 per week. Even at the lowest end of that range, the researchers note, the figures track similar estimates of harm from long waits and crowding published in earlier work.

The research team also examined the impact of so-called corridor care, in which patients receive treatment in non-standard clinical spaces such as corridors, waiting rooms or other areas not equipped for emergency medicine. Corridor care was likewise linked to an increase in the risk of death, broadly in line with the risk associated with the occupancy rate itself. This parallel finding matters for practical reasons: while corridor care is a visible symptom of a department in crisis, it is harder to quantify consistently across hospitals. Occupancy, by contrast, is a simple number that most departments already record, which makes it a far more usable early-warning indicator for hospital managers and health systems trying to gauge when conditions have become dangerous.

Dr McHenry framed the findings against a backdrop of deteriorating emergency care internationally. Emergency department overcrowding, he noted, is an increasing public health concern, with existing evidence showing that long delays increase patient mortality and that crowding is also associated with poor experiences for both patients and staff. He argued that traditional measures of emergency department crowding were developed at a time when the problem was far less severe, and that these older metrics are simply not sufficient to describe the crisis that currently exists in emergency care. The new study, he suggested, provides the direct evidence linking crowding itself, rather than waiting times alone, to patient deaths.

The scale of the study is one of its principal strengths. Data were collected with the help of hundreds of collaborators across 139 emergency departments, giving the researchers what they describe as a detailed and accurate view of how crowding and corridor care affect patients across a whole health system rather than at a handful of sites. Although the study was based on UK hospitals, the researchers argue that given the levels of overcrowding now reported in hospitals around the world, the relationship they observed is likely to hold in many other countries, even allowing for regional differences in how emergency care is organised and delivered.

To translate the findings into practice, the team has built an online risk calculator that allows emergency department staff to estimate the risks to patients when their department is operating beyond capacity. The tool is intended to give clinicians and managers a concrete, quantitative sense of how the conditions on a given day may be affecting outcomes, rather than relying on anecdote or intuition. The researchers say they are already engaging with governments to ensure the research feeds into health service policy, and that the next step is to identify solutions that work in tackling emergency department crowding at its sources.

Independent commentary from the European Society for Emergency Medicine underlined the wider systemic picture. Dr Felix Lorang, a member of the EUSEM abstract selection committee and head of the emergency department at Klinikum Lippe in North Rhine-Westphalia, Germany, who was not involved in the research, observed that around the world the need for emergency care is growing while infrastructure fails to keep pace. Many departments, he said, are operating far beyond capacity, and the phenomenon known as exit block, in which patients are stuck in the emergency department because no inpatient ward beds are available, places an even greater burden on staff. That, in turn, makes it harder for doctors and nurses to deliver the treatment patients need, or even the minimum treatment required to prevent further harm.

Dr Lorang described the research as making it unmistakably clear to patients, medical professionals and hospital managers alike that overcrowding and corridor care mean many emergency patients will not survive. He argued that understaffed and inadequately resourced emergency departments are, in themselves, an independent and dangerous health risk, and that the results are especially critical for governments, politicians and health services because saving lives in emergency care is achievable. The routes he identified are structural rather than clinical: preventing overcrowding through sufficient staffing, and through emergency departments that are adequately planned and equipped for the demand they actually face.

The study’s implications extend well beyond the United Kingdom. Emergency departments in many countries routinely operate above their designed capacity, and the mechanism the research points to, in which the sheer density of patients in a department erodes the safety margin for every individual within it, is not specific to any one health system. As an observational study, the research establishes a strong association rather than a definitive causal chain, and the authors themselves call for further studies to confirm the findings and to arrive at a more precise estimate of the harms from crowding. Even so, the combination of scale, geographic reach and a dose-response pattern, in which risk rises steadily with each increment of occupancy, gives the result unusual weight. If the estimate of hundreds of excess deaths a week is even broadly correct, emergency department crowding ranks among the most consequential and most preventable patient safety problems in modern health care, and the one per cent figure offers policymakers a simple, sobering arithmetic: every increment of relief delivered to a crowded department translates directly into lives that may be saved.

Subject of Research: The association between emergency department overcrowding, corridor care and increased patient mortality

Article Title: Study shows how risk of death rises with rate of overcrowding and corridor care in hospital emergency department

Article References: Study shows how risk of death rises with rate of overcrowding and corridor care in hospital emergency department. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: emergency medicine, hospital overcrowding, corridor care, patient mortality, occupancy rate, emergency departments, observational study, patient safety, exit block, health policy, European Emergency Medicine Congress, risk calculator