SGEM#503: Waiting is the Hardest Part – Factors Associated with ED LOS
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Episode Description
Date: February 13, 2026
Reference: Lang et al. Factors associated with emergency department length of stay in Alberta: a study of patient-, visit-, and facility-level factors using administrative health data. CJEM. 2026 Jan 29.
Guest Skeptic: Dr. Paul Parks is an emergency physician from Medicine Hat, Alberta. He has been the President of the Alberta Medical Association (AMA) Section of Emergency Medicine for many years, the AMA Board of Directors for 9 years, and the Previous President of the Alberta Medical Association. Paul has won the Canadian Association of Emergency Physicians (CAEP) National Teacher of the Year Award and the CAEP Alan Drummond National Advocacy Award.
Case: A 78-year-old man with congestive heart failure (CHF) and chronic obstructive pulmonary disease (COPD) arrives at the emergency department (ED) by ground emergency medical services (EMS) at 15:30 with dyspnea and hypoxia. He’s triaged Canadian Triage and Acuity Scale (CTAS) 2, needs non-invasive ventilation (NIV), diuresis, labs, chest x-ray, and likely admission. The department is packed; multiple admitted patients are boarded in hallway spaces because inpatient beds are unavailable, and nursing assignments are stretched. The patient is placed in the “EMS-PARK” area, which is an extension of the waiting room, and part of a mandatory EMS offload policy. Workup is done while the patient is still technically in the waiting room. The workup and disposition decision happen within a few hours, but transfer to an inpatient bed doesn’t occur until 2-3 days later.
Background: ED length of stay (LOS) can be considered a vital sign of ED operations and the broader acute-care system. When LOS rises, it often signals that the ED is no longer functioning as a short-stay diagnostic and stabilization unit but is serving as a buffer for upstream demand and downstream capacity issues. The consequences are not just operational (hallway beds, delayed assessments, delayed analgesia, delayed imaging), but also human. We covered a study that showed for older patients, one overnight stay in the ED waiting for an inpatient bed was associated with a 4% absolute increase in mortality (SGEM#424). In addition, increasing LOS can lead to clinician burnout and moral injury.
LOS is also tricky because ED crowding is rarely a single-point failure within the ED. Modern crowding frameworks (often summarized as input–throughput–output) remind us that while ED processes matter, some of the most powerful determinants are output constraints. This is especially true when there is access block and inpatient bed scarcity. In other words, you can run an efficient front-end, but if admitted patients cannot be moved to inpatient beds, the system backs up, and ED LOS climbs. As one concrete example of the output challenges many provinces struggle with, in Alberta, 1/3 of our acute hospital capacity, or about 30%, can be occupied by Alternate Level of Care patients. These alternative level of care (ALC) patients have had their acute care needs met, but they cannot be safely discharged from the hospital without specific continuing care resources – home care, assisted living, or long-term care.
We’ve talked about ED crowding on an SGEM Xtra. It covered some of the Zombie Ideas that have been circulating around for decades. The classic one is to blame non-urgent patients for using the ED. They are not responsible for ED crowding. Diverting non-urgent patients away can be dangerous and won’t solve the underlying problem.
CAEP published a position statement on emergency department overcrowding in 2013. CAEP argued for nationally standardized performance benchmarks. The statement also called for system-level solutions to improve flow while recognizing that ED optimization alone cannot solve crowding without hospital-wide and community-wide action. While CAEP’s advocacy has influenced awareness, policy discussion, and accountability framing, significant problems continue into 2026.
Clinical Question: Across Alberta ED visits, what patient-, visit-, and facility-level factors are associated with longer ED length of stay?
Reference: Lang et al. Factors associated with emergency department length of stay in Alberta: a study of patient-, visit-, and facility-level factors using administrative health data. CJEM. 2026 Jan 29.
Population: ED visits drawn from linked Alberta Health Services administrative data for 14 ED facilities in Alberta, covering May 2022 to March 2023.
Exposures: Factors such as age, deprivation measures, EMS arrival, triage acuity (CTAS), primary care continuity, time/day patterns, and facility-level constraints, including emergency inpatient pressure and hospital occupancy; staffing signals (hours worked per nurse) were also examined.
Comparison:Between levels of each exposure, typically relative to a reference category or per-unit change (hospital occupancy, EMS vs non-EMS arrival, different facility types, weekday vs weekend, etc.).
Outcomes
Primary Outcome:ED total length of stay (LOS).
Secondary Outcomes: There were no clearly prespecified secondary outcomes; however, the analysis was stratified by disposition (admitted vs discharged vs other = LWBS, Left AMA, transferred, or died), which functions like a planned subgroup/stratified analysis rather than a distinct secondary endpoint.
Type of Study: This is an observational cross-sectional study using population-based administrative data.
Authors’ Conclusions: “ED length of stay is associated with modifiable factors, including hospital capacity constraints, hours worked per nurse, and healthcare access inequities. Addressing hospital occupancy, optimizing staffing, and improving care coordination across the patient trajectory—such as between the ED, inpatient units, and post-discharge services—may enhance ED efficiency and reduce prolonged stays. Our findings align with established frameworks describing ED overcrowding and support targeted, system-level interventions to improve the efficiency of emergency care.”
Quality Checklist for Observational Studies (Yes/No/Unsure)
Did the study address a clearly focused issue? Yes
Did the authors use an appropriate method to answer their question? Yes
Was the cohort recruited in an acceptable way? Unsure
Was the exposure accurately measured to minimize bias? Unsure
Was the outcome accurately measured to minimize bias? Unsure
Have the authors identified all-important confounding factors? No
Was the follow-up of subjects complete enough? N/A
How precise are the results? Very precise due to a large sample size, resulting in narrow confidence intervals for several of the point estimates.
Do you believe the results? Yes
Can the results be applied to the local population? Unsure
Do the results fit with other available evidence? Yes
Who funded the trial? The authors acknowledge support under the Alberta Atlas of Healthcare Variation initiative.
Did the authors declare any conflicts of interest? Brian R. Holroyd was the Senior Medical Director of the Emergency Strategic Clinical Network of Alberta Health Services at the start of this work. Matthew Pietrosanu was employed by Alberta Health Services for statistical consulting, technical writing, and general advising in the Alberta Atlas of Healthcare Variation initiative, which was expanded to include the preparation of this manuscript.
Results: The dataset included 587,419 ED visits. The median age was 38 years, and 52% were female. Most patients were discharged (68%), with 18% being admitted and 14% left without being seen, left AMA, transferred, or died. The median ED LOS was 3.1 hours overall, and LOS differed substantially by disposition (admitted patients had a much longer median LOS than discharged patients).
Key Result: Facility- and system-level constraints were strongly associated with ED LOS, especially among admitted patients. The more emergency inpatient hours and higher hospital occupancy were associated with longer stays.
Primary Outcome: Across all disposition categories, several patient-level factors were consistently associated with longer ED LOS, including older age, higher material or social deprivation, and arrival by EMS (ground or air). At the visit level, higher triage acuity and certain temporal factors (weekend admissions) were also associated with prolonged LOS, particularly among admitted patients.
However, the largest and most clinically meaningful associations were at the facility level. Measures of hospital capacity strain dominated the results. Higher hospital inpatient occupancy and a greater number of emergency inpatients boarding in the ED were strongly associated with longer LOS, especially for admitted patients. For admitted patients, a one–standard deviation increase in hospital occupancy (approximately 0.11) was associated with a 17% increase in ED LOS, an effect size that dwarfed most patient- and visit-level predictors. This finding strongly supports the concept of access block (outflow from the ED) as the primary driver of prolonged ED stays.
Higher hours worked per nurse were associated with shorter ED LOS in initial models, suggesting a potential staffing effect. However, this association disappeared after accounting for facility-level clustering, indicating that staffing effects may reflect broader organizational or structural differences between hospitals rather than a simple linear relationship with nursing hours.
1) Cross-Sectional Design & Temporality: The biggest design constraint is that this is a cross-sectional observational analysis. Exposures and outcomes are assessed within the same time frame. This means the direction of association can be unclear and may be difficult to determine.
2) Selection Bias: Although the dataset is large, it is not all Alberta EDs.
Reference: Lang et al. Factors associated with emergency department length of stay in Alberta: a study of patient-, visit-, and facility-level factors using administrative health data. CJEM. 2026 Jan 29.
Guest Skeptic: Dr. Paul Parks is an emergency physician from Medicine Hat, Alberta. He has been the President of the Alberta Medical Association (AMA) Section of Emergency Medicine for many years, the AMA Board of Directors for 9 years, and the Previous President of the Alberta Medical Association. Paul has won the Canadian Association of Emergency Physicians (CAEP) National Teacher of the Year Award and the CAEP Alan Drummond National Advocacy Award.
Case: A 78-year-old man with congestive heart failure (CHF) and chronic obstructive pulmonary disease (COPD) arrives at the emergency department (ED) by ground emergency medical services (EMS) at 15:30 with dyspnea and hypoxia. He’s triaged Canadian Triage and Acuity Scale (CTAS) 2, needs non-invasive ventilation (NIV), diuresis, labs, chest x-ray, and likely admission. The department is packed; multiple admitted patients are boarded in hallway spaces because inpatient beds are unavailable, and nursing assignments are stretched. The patient is placed in the “EMS-PARK” area, which is an extension of the waiting room, and part of a mandatory EMS offload policy. Workup is done while the patient is still technically in the waiting room. The workup and disposition decision happen within a few hours, but transfer to an inpatient bed doesn’t occur until 2-3 days later.
Background: ED length of stay (LOS) can be considered a vital sign of ED operations and the broader acute-care system. When LOS rises, it often signals that the ED is no longer functioning as a short-stay diagnostic and stabilization unit but is serving as a buffer for upstream demand and downstream capacity issues. The consequences are not just operational (hallway beds, delayed assessments, delayed analgesia, delayed imaging), but also human. We covered a study that showed for older patients, one overnight stay in the ED waiting for an inpatient bed was associated with a 4% absolute increase in mortality (SGEM#424). In addition, increasing LOS can lead to clinician burnout and moral injury.
LOS is also tricky because ED crowding is rarely a single-point failure within the ED. Modern crowding frameworks (often summarized as input–throughput–output) remind us that while ED processes matter, some of the most powerful determinants are output constraints. This is especially true when there is access block and inpatient bed scarcity. In other words, you can run an efficient front-end, but if admitted patients cannot be moved to inpatient beds, the system backs up, and ED LOS climbs. As one concrete example of the output challenges many provinces struggle with, in Alberta, 1/3 of our acute hospital capacity, or about 30%, can be occupied by Alternate Level of Care patients. These alternative level of care (ALC) patients have had their acute care needs met, but they cannot be safely discharged from the hospital without specific continuing care resources – home care, assisted living, or long-term care.
We’ve talked about ED crowding on an SGEM Xtra. It covered some of the Zombie Ideas that have been circulating around for decades. The classic one is to blame non-urgent patients for using the ED. They are not responsible for ED crowding. Diverting non-urgent patients away can be dangerous and won’t solve the underlying problem.
CAEP published a position statement on emergency department overcrowding in 2013. CAEP argued for nationally standardized performance benchmarks. The statement also called for system-level solutions to improve flow while recognizing that ED optimization alone cannot solve crowding without hospital-wide and community-wide action. While CAEP’s advocacy has influenced awareness, policy discussion, and accountability framing, significant problems continue into 2026.
Clinical Question: Across Alberta ED visits, what patient-, visit-, and facility-level factors are associated with longer ED length of stay?
Reference: Lang et al. Factors associated with emergency department length of stay in Alberta: a study of patient-, visit-, and facility-level factors using administrative health data. CJEM. 2026 Jan 29.
Population: ED visits drawn from linked Alberta Health Services administrative data for 14 ED facilities in Alberta, covering May 2022 to March 2023.
Exposures: Factors such as age, deprivation measures, EMS arrival, triage acuity (CTAS), primary care continuity, time/day patterns, and facility-level constraints, including emergency inpatient pressure and hospital occupancy; staffing signals (hours worked per nurse) were also examined.
Comparison:Between levels of each exposure, typically relative to a reference category or per-unit change (hospital occupancy, EMS vs non-EMS arrival, different facility types, weekday vs weekend, etc.).
Outcomes
Primary Outcome:ED total length of stay (LOS).
Secondary Outcomes: There were no clearly prespecified secondary outcomes; however, the analysis was stratified by disposition (admitted vs discharged vs other = LWBS, Left AMA, transferred, or died), which functions like a planned subgroup/stratified analysis rather than a distinct secondary endpoint.
Type of Study: This is an observational cross-sectional study using population-based administrative data.
Authors’ Conclusions: “ED length of stay is associated with modifiable factors, including hospital capacity constraints, hours worked per nurse, and healthcare access inequities. Addressing hospital occupancy, optimizing staffing, and improving care coordination across the patient trajectory—such as between the ED, inpatient units, and post-discharge services—may enhance ED efficiency and reduce prolonged stays. Our findings align with established frameworks describing ED overcrowding and support targeted, system-level interventions to improve the efficiency of emergency care.”
Quality Checklist for Observational Studies (Yes/No/Unsure)
Did the study address a clearly focused issue? Yes
Did the authors use an appropriate method to answer their question? Yes
Was the cohort recruited in an acceptable way? Unsure
Was the exposure accurately measured to minimize bias? Unsure
Was the outcome accurately measured to minimize bias? Unsure
Have the authors identified all-important confounding factors? No
Was the follow-up of subjects complete enough? N/A
How precise are the results? Very precise due to a large sample size, resulting in narrow confidence intervals for several of the point estimates.
Do you believe the results? Yes
Can the results be applied to the local population? Unsure
Do the results fit with other available evidence? Yes
Who funded the trial? The authors acknowledge support under the Alberta Atlas of Healthcare Variation initiative.
Did the authors declare any conflicts of interest? Brian R. Holroyd was the Senior Medical Director of the Emergency Strategic Clinical Network of Alberta Health Services at the start of this work. Matthew Pietrosanu was employed by Alberta Health Services for statistical consulting, technical writing, and general advising in the Alberta Atlas of Healthcare Variation initiative, which was expanded to include the preparation of this manuscript.
Results: The dataset included 587,419 ED visits. The median age was 38 years, and 52% were female. Most patients were discharged (68%), with 18% being admitted and 14% left without being seen, left AMA, transferred, or died. The median ED LOS was 3.1 hours overall, and LOS differed substantially by disposition (admitted patients had a much longer median LOS than discharged patients).
Key Result: Facility- and system-level constraints were strongly associated with ED LOS, especially among admitted patients. The more emergency inpatient hours and higher hospital occupancy were associated with longer stays.
Primary Outcome: Across all disposition categories, several patient-level factors were consistently associated with longer ED LOS, including older age, higher material or social deprivation, and arrival by EMS (ground or air). At the visit level, higher triage acuity and certain temporal factors (weekend admissions) were also associated with prolonged LOS, particularly among admitted patients.
However, the largest and most clinically meaningful associations were at the facility level. Measures of hospital capacity strain dominated the results. Higher hospital inpatient occupancy and a greater number of emergency inpatients boarding in the ED were strongly associated with longer LOS, especially for admitted patients. For admitted patients, a one–standard deviation increase in hospital occupancy (approximately 0.11) was associated with a 17% increase in ED LOS, an effect size that dwarfed most patient- and visit-level predictors. This finding strongly supports the concept of access block (outflow from the ED) as the primary driver of prolonged ED stays.
Higher hours worked per nurse were associated with shorter ED LOS in initial models, suggesting a potential staffing effect. However, this association disappeared after accounting for facility-level clustering, indicating that staffing effects may reflect broader organizational or structural differences between hospitals rather than a simple linear relationship with nursing hours.
1) Cross-Sectional Design & Temporality: The biggest design constraint is that this is a cross-sectional observational analysis. Exposures and outcomes are assessed within the same time frame. This means the direction of association can be unclear and may be difficult to determine.
2) Selection Bias: Although the dataset is large, it is not all Alberta EDs.