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A 2026 study of 49,034 medical admissions found that every additional four hours patients spent boarding in the emergency department was associated with 8.6 additional hours of inpatient hospital stay — and an 8.4% increase in the odds of death within 30 days.
The numbers are difficult to ignore.
Four additional hours waiting for an inpatient bed.
More than eight additional hours in the hospital afterward.
And potentially consequences extending far beyond the patient who is waiting.
The 2026 study published in the Emergency Medicine Journal analyzed 49,034 medical admissions, 210,334 non-admitted emergency patients, 88,633 ambulance handovers and 146,278 ambulance responses across three emergency departments in England.
Researchers found that additional boarding was associated not only with outcomes among admitted patients, but also with longer ambulance handover times and slower response times elsewhere in the emergency care system.
Emergency department boarding is therefore not simply a question of uncomfortable waiting.
It is a patient-flow problem capable of affecting an entire hospital.
What Is Emergency Department Boarding?
Emergency department boarding, or ED boarding, occurs when a patient remains in the emergency department after the decision has been made to admit or transfer them because the appropriate next care location is not yet available.
The American College of Emergency Physicians' resources on emergency department boarding and crowding distinguish boarding from the earlier stages of emergency care.
A person waiting before evaluation is waiting for emergency care.
A boarded patient has already reached the point where admission or transfer is required but remains in the emergency department waiting for the next destination.
This distinction matters because emergency departments are designed primarily for assessment, stabilization and disposition — not prolonged inpatient care.
It also explains why the distinction between a basic patient trolley and a fully equipped emergency stretcher becomes operationally important. Optium's guide to patient trolleys versus hospital stretchers explores how transport equipment changes when the same platform must also support treatment, imaging and longer periods of patient care.
The Number That Stands Out: 4 Hours Became 8.6 Hours
The 2026 study examined routine data from three emergency departments in England between July 2023 and May 2025.
The researchers analyzed:
49,034 medical admissions.
They also studied more than:
210,000 non-admitted ED patients,
88,000 ambulance handovers,
and
146,000 ambulance responses.
Among admitted medical patients:
Every additional four hours of emergency department boarding was associated with an additional 8.6 hours of subsequent inpatient hospital stay.
The researchers also found:
Every additional four hours was associated with an 8.4% increase in the odds of mortality within 30 days.
These findings come directly from the 2026 Emergency Medicine Journal study on medical-patient boarding.
There is an important word in those statements:
Associated.
This was an observational study.
It does not prove that four hours of boarding directly causes exactly 8.6 additional hospital hours for every individual patient.
But the findings provide a striking illustration of how delays in one part of the hospital can be connected with outcomes elsewhere in the system.
Why Can Four Hours in the ER Be Linked to More Than Eight Extra Hours in the Hospital?
At first glance, this sounds strange.
If a patient waits four additional hours before reaching a ward, why could their later hospital stay be associated with more than eight additional hours?
There is unlikely to be one explanation.
Hospital flow is interconnected.
A delayed transfer can interact with:
clinical review,
diagnostic testing,
medication schedules,
mobility,
nutrition,
therapy assessment,
specialist consultation,
discharge planning,
staffing,
and the timing of routine hospital processes.
A patient reaching a ward several hours later may also reach another part of the hospital's operational cycle.
This is why patient flow cannot always be understood using a simple stopwatch.
A delay at one stage can interact with delays at the next.
A broad 2026 systematic review of 226 studies similarly concluded that emergency department crowding is influenced by input, throughput and output problems and is associated with consequences including increased mortality, treatment delays and prolonged hospital stays. Read the 2026 systematic review of emergency department crowding.
Does ED Boarding Increase the Risk of Death?
This requires careful wording.
The 2026 study found that every additional four hours of boarding was associated with an 8.4% increase in the odds of 30-day mortality.
The reported 95% confidence interval was 5.3% to 11.6%.
The researchers also estimated that, when comparing boarding above versus below four hours in their cohort, the number needed to harm for 30-day mortality was approximately 69.
These figures should not be converted into claims that boarding will cause a death in one out of every 69 patients in every hospital.
The study was observational.
Populations, staffing levels, capacity, clinical severity and hospital systems differ.
Earlier evidence has also been less definitive. A systematic review of 12 studies examining ED boarding and in-hospital mortality found a tendency toward an association but concluded that the evidence available at the time was not strong enough to establish a definitive relationship.
That earlier research can be reviewed in the PLOS ONE systematic review of ED boarding and mortality.
The appropriate conclusion is therefore not:
“Four extra hours causes death.”
It is:
Longer emergency department boarding is an important patient-safety signal, and a growing body of research associates crowding and boarding with adverse outcomes.
ED Boarding Is Not the Same as Waiting in the Emergency Room
These concepts are frequently mixed together.
They refer to different stages of the patient's journey.
Emergency Department Waiting Time
The patient may still be waiting for triage, clinical evaluation, diagnostics, treatment or reassessment.
Emergency Department Length of Stay
This generally describes the entire period between arrival and departure from the emergency department.
Emergency Department Boarding
The patient has reached the stage where admission or transfer is required but remains in the ED because the next destination is unavailable.
This distinction matters operationally.
A crowded waiting room is visible.
Boarding can be less visible because admitted patients may occupy treatment spaces deeper inside the department.
But those occupied spaces can reduce the ED's ability to receive new patients.
The U.S. Agency for Healthcare Research and Quality has long treated emergency department crowding as an organization-wide patient-flow issue rather than simply an ED efficiency problem. See the AHRQ guide to emergency department crowding and patient flow.
Why Does Emergency Department Boarding Happen?
There is no single cause.
Emergency departments sit in the middle of a much larger healthcare system.
Boarding can develop when patients need to leave the ED but the next appropriate location cannot accept them.
Potential contributors include:
limited inpatient bed availability,
high hospital occupancy,
delayed inpatient discharge,
staffing shortages,
delays in cleaning or preparing beds,
limited intensive-care capacity,
limited mental-health placement,
specialty service bottlenecks,
high numbers of incoming patients,
seasonal surges,
and insufficient downstream community or social-care capacity.
The 2026 systematic review grouped crowding pressures into three broad categories:
Input: patients entering the emergency-care system.
Throughput: processes taking place inside the emergency department.
Output: patients being able to leave the ED for the next appropriate destination.
Boarding is predominantly an output problem.
That means making triage faster cannot fully solve a hospital that has nowhere to send admitted patients.
What Happens When Admitted Patients Cannot Leave the Emergency Department?
Imagine an emergency department with a fixed number of staffed treatment spaces.
A patient is assessed.
The clinical team decides that admission is required.
Normally, the patient moves to an inpatient unit.
The emergency treatment space then becomes available for another patient.
But there is no inpatient bed.
The patient stays.
Then another admitted patient stays.
Then another.
Incoming emergencies continue to arrive.
The ED is now trying to perform two different jobs simultaneously:
assessing and stabilizing new emergencies
while also
providing ongoing care to patients who should have progressed to inpatient care.
That is the basic mechanics of boarding.
And it changes what hospital equipment may be required to do.
A stretcher originally associated with patient transport can become a temporary treatment platform.
Optium's Hospital Stretcher Buying Guide by Department explains why emergency, trauma, routine transport, recovery and operating-room environments should not automatically use the same stretcher configuration.
Five More Boarders Can Affect Patients Who Are Not Even in the Hospital Yet
The 2026 study found something particularly important.
The effects associated with boarding were not confined to admitted patients.
For a typical 25-bed emergency department, every five additional medical boarders were associated with approximately:
9.9 additional minutes of ambulance handover time.
7.9 additional minutes in Category 2 ambulance response time.
51.9 additional minutes in Category 3 ambulance response time.
The researchers also found longer ED stays for non-admitted patients.
Think about that chain.
An inpatient bed is unavailable.
So an admitted patient remains in the ED.
An ED treatment space remains occupied.
Another arriving patient cannot move into that space as quickly.
An ambulance may take longer to complete its handover.
That ambulance returns to service later.
The effects of hospital capacity can therefore extend beyond the hospital building itself.
What Is an Ambulance Handover Delay?
When an ambulance reaches a hospital, the vehicle does not automatically become available for its next emergency.
The patient must be transferred from the ambulance team's care into the hospital's care.
During severe crowding, this process can be delayed.
While the crew remains occupied, the ambulance is not available for another call.
The 2026 research found associations between increased medical boarding and longer handover times, as well as slower responses for some categories of ambulance call.
This illustrates an important point:
Hospital patient flow and pre-hospital emergency response are connected systems.
Is Four Hours the Definition of ED Boarding?
No.
This is particularly important because the headline uses four hours.
Four hours is not a universal definition of boarding.
Boarding generally begins once a patient who requires admission or transfer remains in the emergency department waiting for that next destination.
The 2026 study expressed some of its findings in four-hour increments for analytical interpretation.
Four hours is also used in some hospital reporting frameworks. In 2025, for example, ACEP described Leapfrog reporting measures that included the percentage of admitted ED patients experiencing boarding for more than four hours. See ACEP's explanation of the hospital boarding measures.
But:
Four hours is a measurement threshold, not a universal definition of a boarded patient.
How Long Can Someone Be Boarded in the Emergency Department?
There is no single global maximum.
Healthcare systems use different standards, targets and definitions.
In severe circumstances, emergency medicine organizations have documented patients remaining in emergency departments for many hours or even days while awaiting appropriate placement.
ACEP maintains a dedicated emergency department boarding resource center addressing the problem from patient-safety, hospital-capacity and policy perspectives.
The important point is not to normalize prolonged boarding simply because it happens frequently.
When a Stretcher Stops Being Transportation
The word stretcher suggests movement.
A patient is placed on it.
The patient is transported.
The journey ends.
But emergency care does not always work like that.
A patient may:
arrive on a stretcher,
be assessed on it,
receive treatment on it,
move to imaging on it,
return to the emergency department on it,
and then wait for an inpatient bed on it.
Hours can pass.
At this point the stretcher is no longer functioning only as transportation.
It has temporarily become part of the patient's care environment.
That distinction is explored more deeply in Optium's Patient Trolley vs Stretcher guide, which compares routine transport equipment with emergency platforms designed to support positioning, imaging, oxygen, braking and clinical access.
Does a Better Emergency Stretcher Solve ED Boarding?
No.
This is an important distinction.
Emergency department boarding is fundamentally a patient-flow and hospital-capacity problem.
A stretcher cannot:
create an inpatient bed,
discharge a ward patient,
increase nursing capacity,
solve a diagnostic bottleneck,
create mental-health placement,
or fix delayed downstream care.
Hospitals should therefore never treat equipment procurement as the solution to emergency department boarding.
ACEP similarly describes boarding and crowding as problems extending beyond ED operations and requiring broader health-system action.
The equipment question is different:
If a patient does remain on a stretcher for an extended period, what does that stretcher need to support?
What Matters When an Emergency Stretcher Is Used for Longer Periods?
Optium currently has 10 products in its stretcher category, ranging from routine patient transport to emergency, trauma, recovery, shower and operating-room transfer configurations. Explore Optium's complete stretcher range.
That range demonstrates an important procurement principle:
There is no universal “best hospital stretcher.”
The right configuration depends on the patient journey.
Patient Positioning
A patient who remains on a stretcher for an extended period may require more than a flat transport surface.
Backrest adjustment, height adjustment and clinically appropriate positioning functions allow staff to adapt the platform to different stages of care.
For emergency workflows, the EMERGEUM Functional Emergency Stretcher provides hydraulic height adjustment, backrest positioning, Trendelenburg and Reverse Trendelenburg functions.
Mattress Design
The mattress may seem secondary when a product is thought of primarily as a transportation device.
It becomes much harder to ignore when treatment lasts longer than expected.
Mattress thickness, construction, cleanability and pressure-management characteristics should therefore be reviewed according to the intended use.
The EMERGEUM and AVERON Functional Emergency Stretcher both list 10 cm mattress configurations, with optional viscoelastic mattress configurations available.
Height Adjustment
Emergency staff may need to perform examinations, procedures, transfers and repositioning around the same patient.
Working height matters.
For departments that do not require the complete emergency feature set, the ST 62 Hydraulic Patient Stretcher offers hydraulic height adjustment across a 62–87 cm range.
This is one reason a hospital should not assume that every department needs the same product specification.
Mobility and Steering
Emergency departments are rarely empty rectangular rooms.
Stretchers move through:
corridors,
doors,
elevators,
imaging areas,
crowded treatment spaces,
and tight turning zones.
Castor diameter, steering control, pushing geometry and fifth-wheel systems can affect maneuverability.
EMERGEUM uses 200 mm castors, central braking, steering control and a fifth wheel.
AVERON follows a similar emergency-oriented mobility configuration.
Hospitals comparing these systems can start with Optium's department-based stretcher buying guide.
Imaging Compatibility
Emergency and trauma patients may require imaging before their clinical pathway is clear.
Repeatedly transferring a patient simply to obtain an X-ray can add handling steps.
But “X-ray compatible” is not one universal specification.
Hospitals should verify:
whether the mattress platform is radiolucent,
which anatomical areas can be imaged,
whether cassette access is provided,
how the cassette moves,
and whether the configuration actually matches the hospital's radiology workflow.
Optium has a separate detailed guide to X-ray compatible hospital stretchers covering these questions.
For higher-acuity trauma routes, the MOMENTUM Functional Trauma Stretcher uses a full-length dual-deck HPL radiolucent platform and is configured specifically around trauma and imaging workflows.
Braking and Stability
A stretcher has two conflicting jobs.
It must move easily.
Then it must stop and remain stable.
Central braking can simplify that transition in high-volume clinical environments.
This is another reason a routine transport stretcher and an emergency platform should not automatically be treated as interchangeable.
Side-Rail Access
Side rails need to protect the patient while still allowing rapid clinical access.
Emergency departments therefore need to examine how side rails:
lock,
release,
fold,
store,
and interact with transfers.
This becomes especially important when a stretcher functions as a treatment surface instead of merely moving between departments.
Oxygen, IV and Monitoring Support
A patient remaining in an emergency environment may require oxygen, IV therapy or monitoring.
Integrated accessory planning can reduce the number of separate items that staff need to manage during transport.
EMERGEUM includes an integrated 12-liter oxygen-tank holder and height-adjustable IV pole, while monitor shelving is available as an option.
Emergency departments planning the entire resuscitation environment should also consider how stretchers interact with equipment such as the UNICART EMERGENCY crash cart.
Optium's guide to crash carts, medication carts and anesthesia carts explains why those trolley categories should also be specified by workflow rather than by appearance alone.
Not Every Patient Needs an Emergency Stretcher
More features do not automatically mean better procurement.
A full emergency platform may be unnecessarily complex for routine patient movement.
For lower-acuity transport, Optium's ST 72 Patient Stretcher provides a simpler configuration with gas-spring backrest adjustment, full-length side rails, IV pole, oxygen holder and swivel castors.
The ST 62 adds hydraulic height adjustment.
EMERGEUM and AVERON move further toward emergency treatment and imaging workflows.
MOMENTUM is configured more specifically around trauma and radiology.
That hierarchy is exactly why hospitals should specify the workflow before specifying the product.
What Does ED Crowding Do to the Rest of the Hospital?
Crowding is often visible in one place.
Its causes and consequences may exist elsewhere.
The 2026 systematic review of 226 studies identified consequences including:
increased mortality,
treatment delays,
longer inpatient stays,
higher rates of patients leaving without being seen,
and reduced patient satisfaction.
It also found that output-focused interventions such as active bed management and earlier discharge protocols require coordination across the hospital.
This matters because it challenges a common assumption:
A crowded emergency department does not necessarily mean the emergency department itself is operating inefficiently.
Sometimes the emergency department is simply the place where a hospital-wide capacity problem becomes visible.
What Can Hospitals Do About ED Boarding?
There is no single intervention that solves boarding in every hospital.
The causes vary.
Potential approaches identified across research and professional guidance include:
active bed management,
earlier inpatient discharge processes,
better coordination of discharge-dependent services,
improved hospital-wide visibility of bed status,
surge-capacity planning,
appropriate observation pathways,
better coordination between inpatient and emergency teams,
reducing avoidable diagnostic and consultation delays,
and matching staffing resources to predictable demand.
The 2026 systematic review of ED crowding interventions found promising strategies but also emphasized that evidence quality remains variable and that system-level approaches are required.
ACEP likewise argues that emergency physicians cannot resolve a system-wide boarding problem alone. Read ACEP's position on hospital-wide boarding solutions.
Frequently Asked Questions About Emergency Department Boarding
What does boarding mean in an emergency department?
ED boarding generally means that a patient remains in the emergency department after the decision to admit or transfer them because the appropriate next destination is not yet available.
Is ED boarding the same as waiting in the emergency room?
No.
Waiting may occur before assessment, diagnosis or treatment.
Boarding generally occurs after a patient has already reached the point where admission or transfer is required.
Why are admitted patients kept in the ER?
Common reasons include lack of staffed inpatient beds, high hospital occupancy, delayed discharges, staffing shortages, specialty placement requirements and other downstream capacity constraints.
Is ED crowding caused by too many non-emergency patients?
The evidence does not support such a simple explanation.
Modern crowding models include input, throughput and output factors, with inpatient boarding identified as a major output problem.
Does four hours define ED boarding?
No.
Four hours is used as a measurement threshold in some studies and reporting systems, but it is not a universal definition.
Does ED boarding increase hospital length of stay?
A 2026 study of 49,034 medical admissions found that every additional four hours of boarding was associated with 8.6 additional hours of subsequent inpatient stay.
Does ED boarding increase mortality?
Research has found associations between boarding, crowding and adverse outcomes, but the strength of evidence differs between studies.
The 2026 study found an 8.4% increase in the odds of 30-day mortality for each additional four hours of boarding. Earlier systematic-review evidence was more mixed, which is why association should not be presented as simple causation.
Can ED boarding affect ambulance response?
Yes.
The 2026 study found associations between the number of medical boarders, longer ambulance handover times and slower response times for some ambulance categories.
Can a hospital solve boarding by buying more stretchers?
No.
A stretcher creates another physical patient platform.
It does not create inpatient capacity.
Hospitals should solve the underlying flow problem while ensuring that equipment used during unavoidable delays is appropriate for the actual clinical workload.
What is the difference between a patient trolley and an emergency stretcher?
Terminology overlaps internationally, but functionality can differ considerably.
A routine trolley may focus primarily on safe movement.
An emergency stretcher may additionally provide hydraulic positioning, central braking, steering control, X-ray access, oxygen storage and other functions needed while the patient remains on the platform.
For a detailed comparison, see Optium's Patient Trolley vs Stretcher guide.
What should hospitals compare when buying an emergency stretcher?
Hospitals should consider the intended department and patient journey first.
Relevant specifications can include:
positioning,
height range,
mattress configuration,
safe working load,
side rails,
braking,
steering,
X-ray access,
oxygen storage,
IV support,
accessories,
cleanability,
maintenance,
and spare-parts availability.
The full procurement framework is covered in Optium's Hospital Stretcher Buying Guide by Department.
From Transport Device to Temporary Care Platform
Emergency department boarding exposes an uncomfortable mismatch.
The hospital intends the patient to move onward.
But the patient remains.
The stretcher that was partly designed around movement may therefore be required to support:
positioning,
observation,
imaging,
nursing care,
monitoring,
clinical access,
and repeated patient interaction
for much longer than originally expected.
This does not mean a stretcher should replace an inpatient hospital bed.
It should not.
It means hospitals should purchase emergency equipment based on how their departments actually operate — including predictable periods of crowding and prolonged patient stays.
Hospitals comparing different patient journeys can explore Optium's complete stretcher and clinical transport range.
EMERGEUM: When Transport and Emergency Care Overlap
For emergency departments where a stretcher must support both movement and treatment, Optium's EMERGEUM Functional Emergency Stretcher combines:
hydraulic height adjustment,
Trendelenburg and Reverse Trendelenburg,
gas-spring-assisted backrest adjustment,
a 10 cm mattress,
X-ray-translucent mattress platform,
full-length sliding X-ray cassette access,
12-liter oxygen-tank storage,
collapsible side rails,
200 mm castors,
central braking,
steering control,
and a fifth wheel.
Its stated safe working load is 250 kg, with a height range of 58–88 cm.
Hospitals should select any stretcher based on their actual workflow and approved clinical requirements rather than assuming that the most feature-rich configuration is automatically the correct one.
For departments comparing emergency, trauma, ward, recovery and operating-room workflows, see the Optium Hospital Stretcher Buying Guide.
Four Hours Can Reach Much Further Than Four Hours
The most striking message from the 2026 research is not simply that some patients waited longer.
It is how that delay was associated with events elsewhere in the system.
4 additional hours of ED boarding.
8.6 additional hours of inpatient stay.
8.4% higher odds of 30-day mortality.
And as the number of medical boarders increased:
ambulance handovers became longer,
some ambulance response times increased,
and
other emergency patients experienced additional delays.
These figures should not be interpreted as proof of simple cause and effect.
But they illustrate an important reality:
The emergency department does not exist in isolation.
When patient flow stops in one part of a healthcare system, the effects can travel in both directions.
Upstream toward ambulances and incoming emergency patients.
Downstream toward inpatient wards and discharge.
ED boarding may look like one patient waiting on one stretcher.
In reality, it can be a visible signal that the entire hospital system is waiting.
Methodology and Sources
The primary figures used in this article come from the 2026 study “Medical patient boarding in the emergency department as a source of crowding and delay-related harm, impacting patient outcomes and the efficiency of urgent and emergency care,” published in the Emergency Medicine Journal.
The study used retrospective data from three emergency departments in England between 2023 and 2025.
It included 49,034 medical admissions, alongside data from non-admitted emergency patients, ambulance handovers and ambulance responses.
The major figures discussed in this article are associations reported by that research and should not be interpreted as universal causal effects.
Read the original Emergency Medicine Journal research.
Additional evidence and definitions were reviewed from:
Emergency Department Crowding in the Modern Era: A Systematic Review (2018–2025)
American College of Emergency Physicians — Emergency Department Boarding and Crowding
Agency for Healthcare Research and Quality — The Need to Address Emergency Department Crowding
Clinical note: This article provides general educational and healthcare-planning information. It does not provide individual medical advice or replace local clinical protocols.