Case Management Insider

Managing Length of Stay Using Patient Flow – Part 1

By Toni Cesta, PhD, RN, FAAN
Senior Vice President
Lutheran Medical Center
Brooklyn, NY

The focus on patient flow in the hospital setting began in the 1990s, when emergency department (ED) overcrowding became a serious threat to patient safety and quality of care. ED overcrowding was not limited to a geographic region or particular city. It was a widespread phenomenon that seemed to reflect greater issues in health care. Back-ups in the emergency room were reflective of issues of patient flow but also demonstrated a national problem. That problem had to do with the fact that many patients used the emergency department as their first route of entry to the health care system. There are many theories as to why this was true. It seemed to be more prevalent among the indigent and under-served who did not have rapid access to a primary care provider. Patients preferred to go to an ED where they knew they would be treated quickly. In addition, the increase in uninsured individuals also affected the numbers of patients using emergency rooms.

Combined with these issues were additional national issues:

  • rising bed demand;
  • limited bed / treatment capacity;
  • the need to manage cost and length of stay;
  • the need to improve customer service and the patient experience.

Many organizations began to take a systematic look at these issues to identify the causes, correct them, and prevent them from reoccurring.

What Is Patient Flow?

In order to apply the concepts and strategies related to patient flow, one must first understand what it really means from a practical perspective. A useful definition might be the following:

“Patient flow is a disciplined way of looking at all the patient care processes that support patients as they travel through the health care experience.”

These processes occur all along the continuum of care, regardless of where care is being provided. We typically think of patient flow in terms of patient hand-offs across the continuum, and we think of it in terms of the progression of patient care within the acute care setting. The definition above allows us to think of patient flow in broad terms. Many of the care processes in which case managers work have evolved over time and haphazardly. Organizations did not always take the time to identify and correct process delays as they did not consider them in terms of length of stay, cost and quality of care as we do today. The segregation of hospital departments and disciplines maintained and sometimes fostered broken systems and processes. In some instances, ancillary departments were not aware of the effect of delays in their departments on the hospital’s throughput and patient flow. For example, delays in radiology can have an effect on patient care in terms of diagnosis, treatment and discharge.

However, it was unusual for hospitals to have objective data identifying the actual time delay from when a physician ordered a test until the test was completed. Staff often knew where delays were happening, but this information was anecdotal and not quantified in any objective way. Information systems were not available to support this kind of work. For all these reasons, case managers often found themselves working around broken systems in an effort to facilitate length of stay and patient flow. It wasn’t until case managers began to collect variance or avoidable delay data that hospitals began to gain a better understanding of where process delays could be improved.

Patient Flow and Quality of Care

Hospitals also began to realize that there was a dynamic relationship between bad process flow and quality of care. Patient flow issues encompassed more than just process issues affecting length of stay and cost of care. They also negatively affected the quality of care. Hospitals found that the following had strong effects on quality care:

  • wrong medications or treatments including over-utilization of medications and treatments;
  • misuse of product and personnel resources;
  • delays in care processes, including core measures.

In addition, hospitals had to ensure that patients, as customers of the hospital, were satisfied with their care. As patients became more educated, the need to ensure that patients were satisfied customers became more and more important. As we reviewed in the last few issues of Case Management Insider, quality of care is tied to reimbursement. These ties go well beyond maximizing a DRG payment by controlling length of stay and resource consumption. They go right to the heart of patient care through core measures, readmissions, hospital-acquired conditions and patient satisfaction scores, among others.

Queuing Theory

Queuing theory has become part of the foundation of patient flow theory and implementation as it is applied to hospital processes. It is understood that as hospital occupancy rates increase, wait times will increase as well. In fact, as occupancy rates surpass 90%, hospital processes actually begin to slow down as more patients queue up for resources that do not increase as occupancy increases. For example, despite a high occupancy rate, the hospital retains the same number of CAT scan and MRI machines, the same amount of stress testing equipment, and so on. Therefore, more patients are lining up for the same number of resources.

Queuing theory is based on the following four premises (Jensen, Mayer, Welch & Haraden, Leadership for Smooth Patient Flow, Health Administration Press, 2007):

  • As occupancy increases, wait time and service delays increase exponentially.
  • Unscheduled or uncontrolled arrivals will behave in characteristic fashion.
  • A balk is an arriving customer who sees a long line and does not seek service.
  • Reneging occurs when a customer gets off a line.

Applying Queuing Theory to Hospital Processes

The elements of queuing theory are applicable to hospital care processes and reinforce commonly seen patterns that case managers deal with every day. As we just discussed, increased occupancy rates will result in delays in patient care processes. Even beyond this are expected delays that happen almost every day in our organizations. If asked what time of day your hospital experiences most of its daily delays in the emergency department, most members of your organization would answer by saying that their most common time for backups in the ED is mid-to-late afternoon. If your hospital has issues of high capacity, it is likely that your patterns happen at roughly the same time every day as patient walk-ins and ambulance traffic begin to increase.

We should also note that the PACU (post-anesthesia care unit) gets backed up on busy days around the same time as well. These patterns are predictable, but are they preventable? If one considers that they happen in characteristic or predictable fashion, then one might also consider that the ED can adjust resources and other care processes in anticipation of these patterns.

Balking will occur in hospitals when patients are aware of these common patterns of delay. We might overhear a neighbor saying, “I don’t go to St. Elsewhere’s emergency room because there are always long waits there. They are so disorganized and I don’t want to spend my whole day there.” Reneging will occur when patients come to the emergency room, but after being triaged and waiting to see the doctor for a while, may walk out without the physician seeing him or her. This can be a serious problem, as these patients may have a serious medical problem for which they need immediate treatment. This also leaves a negative impression in the community that the hospital serves.

Since most hospitals experience patterned delays, the application of queuing theory as you access your commonly experienced bottlenecks can be helpful. Emergency department delays have become a national phenomenon that became critical in the late 1990s with over half of hospitals reporting some amount of through-put delay in their EDs.

The Joint Commission and Patient Flow

Because of the national issues associated with emergency department delays, in 2005, The Joint Commission added a new standard for patient flow. The standard, LD.3.15, states “The leaders develop and implement plans to identify and mitigate impediments to efficient patient flow throughout the hospital.”

Elements of performance for LD.3.15 include:

  1. Leaders assess patient flow issues within the hospital, the impact on patient safety, and plans to mitigate that impact.
  2. Planning encompasses the delivery of appropriate and adequate care to admitted patients who must be held in temporary bed locations; for example, post anesthesia care unit and emergency department areas.
  3. Leaders and medical staff share accountability to develop processes that support efficient patient flow.
  4. Planning includes the delivery of adequate care, treatment, and services to those patients who are placed in overflow locations, such as corridors.
  5. Specific indicators are used to measure components of the patient flow process and address the following:
    1. available supply of patient bed space;
    2. efficiency of patient care, treatment, and service areas;
    3. safety of patient care, treatment, and service areas;
    4. support service processes that impact patient flow.
  6. Indicator results are available to those individuals who are accountable for processes that support patient flow.
  7. Indicator results are reported to leadership on a regular basis to support planning.
  8. The hospital improves inefficient or unsafe processes identified by leadership as essential to the efficient movement of patients through the hospital.
  9. Criteria are defined to guide decisions about initiating diversion.

Demand and Capacity Management

Demand and capacity management provide us with certain strategies for managing our organization’s issues of overcrowding and processing delays from a proactive point of view. Some of these strategies include:

  • identifying commonly occurring bottlenecks and delays;
  • smoothing demand by identifying off-peak service opportunities;
  • promoting clinically appropriate discharge times;
  • sharing capacity when appropriate — real estate is a commodity;
  • cross-training where appropriate.

Case managers play an important role in demand and capacity management. Later in this two-part series we will discuss case management data collection to facilitate the identification of these commonly occurring bottlenecks so they can be corrected on a go-forward basis. Once these bottlenecks have been identified, it will become important to take a look at the patterns of delay and see whether there are opportunities to extend or enhance the hours of a particular service. This may mean providing the service during extended or off-hours, or even adding staff members to provide more opportunities for providing the service.

Discharging Patients When They Are Clinically Ready

Many hospitals have set targets for discharge time. In some organizations that may be 10 am, while in others it may be 11 am. It is important that discharged patients leave the building as early in the day as possible. There is, however, another way to look at discharge times that is more consistent with demand and capacity management theories. This has to do with discharging patients when they are clinically ready for discharge, regardless of the time of day. By discharging patients throughout the day and early evening, bottlenecks can be smoothed out or avoided entirely. By spreading the admission and discharge process out over more hours, it reduces the work load in the admitting office, nursing floors and ancillary services.

Imagine how taxing it is to all the related systems in the hospital when “batching” of discharges occurs. Batching of any kind of work, such as laboratory testing, slows that process down, causing increased turn-around-time and a longer overall process. In addition, patients who leave in the late afternoon or early evening, because they are clinically ready, may appear to be “late discharges” when in reality they are “early discharges.” In less contemporary case management systems these patients would otherwise have stayed in the hospital until the next day. Today, as opportunities to reduce length of stay are less obvious, discharging patients when clinically appropriate, regardless of the time, makes sense as another source of length of stay reduction. Of course, the discharge time should not be so late in the evening that the patient may be put at risk. Common sense must always prevail.

Vacant Hospital Areas

Looking at vacant areas of the hospital during periods of overcrowding is another important technique for demand and capacity management. Some examples would include:

  • Use closed or unused clinical areas during peak times.
  • Consider a “holding area” for admitted patients waiting for inpatient beds, and staff this area appropriately.
  • Consider a dedicated area for observation patients outside of your ED if your reimbursement schemes will support this.
  • Expand the PACU space when necessary.
  • Consider a discharge lounge.
  • Consider the use of hall beds when necessary.

Even if you have tried one or more of these strategies in the past, you may want to consider trying them again. As the healthcare system continues to evolve, and as dollars continue to be tight, circling back to methods of the past with renewed interest can sometimes be helpful. Holding area, discharge lounges, and dedicated observation areas are all examples of strategies that have been around for a while and that you may have tried and abandoned at some point. Try them again. They may just work this time!

When patient flow is well-managed, outcomes can be improved in three ways:

  1. improved patient safety;
  2. improved quality of care;
  3. improved operational efficiency.

When patients receive the clinical care they need in a timely fashion, this reduces the likelihood of a treatment delay that can result in a poor outcomes for the patient. Patients are not exposed to the acute care environment for any longer than they need to be, thereby reducing their exposure to errors, infections or falls. By improving care processes and reducing delays in service, the quality of care to the patients is improved. Patients are treated when clinically necessary and without long delays; this is fundamental to achieving quality of care and improving patient safety.

Finally, operational efficiency, including service delivery turn-around-times, is enhanced, having a positive effect on the bottom line of the hospital. Clearly, when the hospital positively impacts on cost, it also positively impacts on quality of care. These issues are entwined and directly relate to each other. This is why case managers are so integral to the patient flow process. They are the staff that provide the balance and the link between the clinical and financial worlds.


This month we have discussed the fundamentals of patient flow and its related theories. We reviewed the concepts of demand and capacity management as they apply to the hospital setting. Patient flow requires daily diligence and attention. It should not be something focused on only on busy days, but should be managed each and every day. By taking a proactive approach to patient flow, the number of days your hospital will be bottlenecked can be reduced. Patient flow needs to be part of the daily activities of every case management department and should be factored in as a core role and function in a contemporary case management department. Patient flow needs to be addressed at the patient, departmental, and hospital level.

In next month’s issue we will continue our discussion on patient flow with a detailed review of specific examples that any case management department can use. We will also review all the departments and disciplines that contribute to patient flow and their role in it.