Emergency department volume and acuity as factors in patients leaving without treatment.

Objectives: Patients who leave emergency departments (EDs) without treatment represent potential personal and hospital liability. Many department-dependent factors have been linked to patients who leave without treatment (LWT) in high-volume EDs. The authors studied how department volume and acuity influence LWTs in a small, low-volume, university-affiliated ED.

Methods: Through retrospective ED census review, LWTs, department volume, and department acuity were recorded for 12-hour shifts over 1 year. Department acuity is defined as patients requiring resuscitation or admission.

Results: Over a 12-month period, 629 of 18,664 patients left the ED. When shift volume exceeded 25 patients, there were significantly more LWTs. When department acuity exceeded four patients per shift, there were also significantly greater numbers of LWTs. More than half of all shifts exceeded one of these thresholds.

Conclusions: Thresholds of 25 patients and an acuity of five patients per shift were associated with significant increases in LWTs, suggesting possible per-physician maximum patient loads before an increased risk of LWT patients.

Key Words: emergency department acuity, emergency department volume, emergency services, leave without treatment

**********

Any patient who leaves the emergency department (ED) without being seen and treated by a physician represents potential liability to him or herself and the hospital. (1) Unfortunately, this scenario is not rare; previous studies report a rate of patients who leave without treatment (LWT) between 0.1 and 15%, with most falling in the 3 to 5% range. (2-6) Furthermore, this phenomenon is not without widespread consequence, as many of those who leave without treatment will seek medical treatment elsewhere, including other emergency departments; these "re-visits" exacerbate already near-critical ED overcrowding. (2,7-12)

Conventional logic would suggest that "not-sick" patients will self-triage and selectively leave the ED. Indeed, most LWT patients present with "low-acuity" problems, as classified by initial triage. (2) However, this self-selection is not reliable, as many LWT patients who re-present with acute myocardial infarction are later admitted or require emergency surgery. (8,11,13)

At-risk populations are not immune to this phenomenon. LWT rates in pediatric EDs are similar to adult rates, even though the sick child is likely not the one making the decision to depart. (5,14) Likewise, patients with psychiatric and drug- or alcohol-related complaints may represent a disproportionate number of LWTs. (15,16) Suicidal and self-harm patients presenting to a British accident and emergency department who did not receive a psychiatric assessment were twice as likely to commit further self-harm in the next year than those who were evaluated. Almost half of the patients who did not receive a timely evaluation proceeded to leave without treatment. (17) It could be argued that these patients may not be making wise decisions and are at as great a risk for potential adverse outcomes as patients presenting with other medical complaints.

There are two distinct sets of characteristics that will determine whether an ED visit is completed: department-dependent and patient-dependent. Department-dependent variables include ED volume; the number of admissions through the ED; and time spent waiting for a room, the doctor, or laboratory results. Patient-dependent factors include demographics, and the attitudes and perceptions that relate to the visit. Both sets have been explored, and potential solutions have been attempted.

Previous research has identified the following department-dependent variables in patients' decisions to leave without treatment: waiting room time, ED volume, total resuscitations in the ED, and total hospital admissions through the ED. Similarly, the patient's perception of a "busy" ED and recent psychological distress are related to leaving without treatment. (2,3,7,9,10,16,18)

Besides identifying potential populations that are more prone to leave without treatment, little can be done about patient-dependent variables. Department-dependent factors can be more easily addressed; however, even drastic interventions, such as adding additional beds or creating novel "acute care units," do not eliminate this phenomenon. (4)

These studies, however, were conducted at large hospitals with annual ED censuses above 50,000 and/or staffed by multiple physicians, and may not be applicable to smaller departments. This study investigates ED volume and department acuity as factors in patients leaving without treatment from a small, university-affiliated ED with an annual census below 20,000, and staffed by a single attending physician.

Materials and Methods

This study was conducted in a medical university-affiliated ED. There is no associated emergency medicine residency program. This facility is continuously staffed by a single attending physician, interns from various specialties that rotate through the ED, and, occasionally, a physician assistant.

This ED houses the only secure seclusion rooms for psychiatric patients in the county. There is a private hospital, a Veterans Administration hospital, and a Level I trauma center within three city blocks of the studied ED. Because of these factors, the general population is mostly uninsured and suffering from medical or psychiatric complaints.

Using a retrospective ED census review, patient volume and numbers of admissions, resuscitations, and LWTs were recorded for 12-hour shifts over a 1-year period. Patients were divided into shifts on the basis of time of initial registration/triage in the ED.

For this study, "LWT" includes patients who registered to be seen but left before definitive treatment was given, including those who left against medical advice; those who left before assessment, treatment, or discharge planning was complete; or who did not answer multiple calls from the waiting area. "Department acuity" refers to the number of patients requiring ED resuscitation efforts or admission to the hospital. Department acuity was chosen over individual patient acuity because previous studies have shown that patient acuity is not a reliable indicator of LWT (2,8,11); department acuity may better reflect the global demands on the staffing physician.

Patient-specific information (eg, demographics, chief complaint) was not collected, in order that focus would be kept on department-dependent variables. This study was reviewed by the institutional review board and classified as exempt regarding consent and disclosure.

Two-tailed Pearson coefficients were used to determine the significance of the overall trend of LWTs as a function of increasing volume or department acuity. Two-tailed Student t tests were used to compare numbers of LWTs over increasing intervals of volumes and acuities to periods of no acuity (0-1 patients per shift) or very low volume (5-10 patients per shift).

Results

Between July 1, 2000, and June 30, 2001, 18, 644 patients registered for care in the ED. Of these, 629 were classified as LWTs (3.4%). Median volume was 23 patients per 12-hour shift, and median department acuity was 3 patients per shift.

Increasing ED volumes were associated with more LWTs (Fig. 1), reaching statistical significance when volume exceeded 25 patients per shift. Pearson coefficient established P < 0.001 for this trend.

Increasing LWTs were also associated with higher ED acuity (Fig. 2). There was a slowly increasing trend through a total of four admissions or resuscitations; however, LWTs doubled when department acuity reached or exceeded five patients per shift (P < 0.05). This overall trend demonstrated P < 0.001 with a Pearson coefficient.

Overall rates of leaving without treatment also trend upward, reaching 4.7% at extreme ED volumes and 4.4% with high acuity (Table). Although these data points are statistically significant (P < 0.05), the overall relationship between increasing volumes and acuities and increasing rates of leaving without treatment was not. Of 730 total shifts, almost half (349) had total volume greater than 25 and more than 20% (163) had an acuity of 5 or more events per shift.

Discussion

We chose to use "department acuity" as a study variable instead of the typical "patient acuity" for a few reasons. Other studies show that triage classification is not a reliable predictor of who might leave without treatment, because high-acuity patients will still leave without treatment, and low-acuity patients stay to be seen. (2-12) Individual patient acuity is a patient-dependent variable that the ED can recognize, but not plan for or predict. Department acuity offers more of a snapshot of how busy the department and our lone attending physician may be, independent of overall volume. This is now a department-dependent variable that could be anticipated by evaluating past trends and compensated for in future staffing plans.

Our LWT rates are similar to those seen at larger institutions despite smaller volumes and arguably less individual patient acuity (due to the close proximity of the trauma center and main university hospital's ED). Interestingly, the thresholds of increased LWTs come when volume averages 2.1 patients per physician per hour, below the American College of Emergency Physician's productivity guide of 2.6 patients per physician per hour. This result was not expected and there is no obvious explanation. There are currently no plans to address the observed LWT numbers at this time, as the ED is scheduled to close in the next few years. Review of the literature, though, shows that many emergency departments are striving to reduce the numbers of LWTs, with solutions ranging from the simple to the complex.

Lombardi et al (19) lowered their LWT rate by using periodic announcements of expected wait time. This strategy allows misinformation to set up increased customer satisfaction by seeing patients sooner than they are told to expect. Such a practice, though, could actually contribute to some decisions to leave without treatment if the patient considers the predicted wait time to be too long. Announcing an underestimated time would also be deleterious to patient satisfaction.

Johns Hopkins created an innovative Acute Care Unit to alleviate ED congestion by attacking the back end of ED flow; (4) this strategy clears beds otherwise occupied by long-stay patients. Patients awaiting an inpatient bed, consultation from other specialties, or prolonged diagnostic and treatment modalities do not clog the ED, allowing quicker patient turnover. Their positive results are confounded, though, by increasing total attending physician coverage by 7 hours daily, shifting acuity away from the ED and to the new unit, and effectively adding 14 new beds and 3 procedure rooms. The new unit received 15% of ED volume and accounted for 25% of ED admissions, directly impacting the two variables evaluated in the present study.

Partovi et al (6) halved their LWT rate by assigning a faculty physician to the triage area during high-volume periods. The main advantage was the ability to directly discharge patients with minor complaints, thereby reducing practical ED volume. The cost of triage during these times was an estimated $12 per patient; the cost rose to over $19 per patient if implemented full-time. Although this solution had a dramatic impact on LWT rate, the cost may be prohibitive to smaller EDs; implementation would be near impossible in an ED staffed by a lone physician.

Fernandes et al (20) were able to drop their LWT rate to about 1% by using continuous quality improvement to streamline a "fast-track" program to treat nonurgent patients. To achieve this, they added both staff and space to the fast-track area, and modified triage guidelines over several phases. It is unclear which of these improvements had the greatest effect on LWTs, but overall length-of-stay decreased as each solution was implemented. (21, 22) Establishing such an area in smaller EDs would be impractical because there is not enough overall volume to support it. However, streamlining triage and discharge processes could impact departments of all sizes.

A crucial decision surrounding this issue is economic and medico-legal: what is the acceptable number of potential customers/litigants that can leave the ED without being treated? Each person represents lost revenue from lost billable charges and a potential lawsuit if a bad outcome occurs. There may be a calculable risk-benefit ratio that can define this point for each ED, and crossing this threshold should trigger implementation of potential solutions.

Another crucial decision surrounds the best way to quantify LWTs: is the absolute number of LWTs or the rate of LWTs the most important? For example, consider a 5% LWT rate; although this number may remain constant as ED volumes rise from 20 to 60 patients per shift, the absolute number of walk-outs triples. From a customer service viewpoint, maintaining a low but steady LWT rate across increasing patient volumes suggests an efficient system that controls department-dependent variables. However, potential medico-legal risk depends on the total number of LWTs if each patient can be considered a future litigant.

Achieving a no-walkout scenario is impossible, regardless of the resources spent to combat LWTs. Identifying individual department weaknesses and bottlenecks may allow risk minimization. Increasing attending physician coverage hours, streamlining potential areas of stagnation, and reinforcing ancillary staff and services are logical areas to begin.

Some limitations of this study stem from the fact that, unfortunately, the original hand-written census logs do not include other potential study variables. Time spent in the waiting room, initial triage classification, and patient demographics were not recorded. Patients' chief complaints and discharge diagnoses are noted, but analyzing these noncomputerized records for trends was beyond the authors' means. Also, there is no way to correlate resident and physician assistant staffing levels or individual attending physician schedules to the observed LWT trends. However, staffing levels remain fairly constant, and it is unlikely that variations in individual physician practices would account for these trends over such a relatively long study time.

There is no way to determine the rate of return visits to this ED or subsequent visits to one of the three other EDs within walking distance. Previous evidence supports the argument that these patients may make multiple ED visits, potentially exacerbating current overcrowding and ambulance diversion crises. (2,7,8,10,12)

Conclusion

In this setting, ED volumes exceeding 25 patients and department acuity of greater than 4 patients per 12-hour shift were associated with significantly more patients leaving without treatment.

I think we consider too much the good luck of the early bird, and not
enough the bad luck of the early worm.
--Franklin D. Roosevelt

Emergency Department volume
per 12-hour shift            LWT per shift

 5-10                        0.28
11-15                        0.31
16-20                        0.57
21-25                        0.63
26-30                        0.68*
31-35                        1.13*
36-40                        1.34**
41+                          2.1**

Fig. 1 Emergency department volume as a factor in patients leaving
without treatment. *P < 0.005, **P < 0.01 versus baseline.

Note: Table made from bar graph.

Admissions/Resuscitations per
12-hour shift                  LWT per shift

0-1                            0.56
2                              0.62
3                              0.78
4                              0.74
5                              1.56*
6+                             1.45*

Fig. 2 Emergency department acuity as a factor in patients leaving
without treatment. *P < 0.01 versus baseline.

Note: Table made from bar graph.

Table. Absolute number and rate of patients leaving without treatment
across increasing patient volumes and acuities (a)

        No. of                  LWT
        12-h shifts  LWT/shift  rate (%)

Volume
  5-10   25           0.28        3.2
 11-15  121           0.31        2.3
 16-20  155           0.57        3.2
 21-25   90           0.63 (b)    2.8
 26-30   90           0.68 (b)    2.4
 31-35   90           1.1 (c)     3.4
 36-40   76           1.3 (c)     3.5
 41+     83           2.1 (c)     4.7 (b)
Acuity
 0-1    140           0.56        2.9
 2      134           0.62        2.8
 3      173           0.78        3.1
 4      120           0.74        2.8
 5+     163           1.47 (c)    4.4 (b)

(a) LWT, leave with treatment.
(b) P < 0.05.
(c) P < 0.001 versus baseline.

Accepted November 12, 2003.

Presented at the 2003 Society for Academic Emergency Medicine Annual Meeting, Boston, MA, May 2003, and awarded Best Medical Student Research Presentation (Clinical Science).

References

1. Tammelleo A. Legal case briefs for nurses. Regan Rep Nurs Law 1994;34:3.

2. Liao HC, Liaw SJ, Hu PM, et al. Emergency department patients who leave without being seen by a doctor. Chang Gung Med J 2002;25:367-373.

3. Stock LM, Bradley GE, Lewis RJ, et al. Patients who leave emergency departments without being seen by a physician. Ann Emerg Med 1994;23:294-298.

4. Kelen GD, Scheulen JJ, Hill PM. Effect of an emergency department managed acute care unit on ED overcrowding and emergency medical services diversion. Acad Emerg Med 2001;8:1095-1100.

5. Browne GJ, McCaskill ME, Giles H, et al. Paediatric walk-out patients: characteristics and outcomes. J Paediatr Child Health 2001;37:235-239.

6. Partovi SN, Nelson BK, Bryan ED, et al. Faculty triage shortens emergency department length of stay. Acad Emerg Med 2001;8:990-995.

7. McNamara K. Patients leaving the ED without being seen by a physician: is same-day follow-up indicated? Am J Emerg Med 1995;13:136-141.

8. Khanna R, Chaudhry MA, Prescott M. Emergency department patients who leave without being seen by a doctor. Eur J Emerg Med 2000;7:79-80.

9. Fernandes CM, Daya MR, Barry S, et al. Emergency department patients who leave without seeing a physician: the Toronto Hospital experience. Ann Emerg Med 1994;24:1092-1096.

10. Bindman AB, Grumbach K, Keane D, et al. Consequences of queuing for care at a public hospital emergency department. JAMA 1991;266:1091-1096.

11. Baker DW, Stevens CD, Brook RH. Patients who leave a public hospital emergency department without being seen by a physician. JAMA 1991;266:1085-1090.

12. Sainsbury S. Emergency patients who leave without being seen: are urgently ill or injured patients leaving without care? Mil Med 1990;155:460-464.

13. Lee TH, Short LW, Brand DA, et al. Patients with acute chest pain who leave emergency departments against medical advice: prevalence, clinical characteristics, and natural history. J Gen Intern Med 1988;3:21-24.

14. Dershewitz RA, Paichel W. Patients who leave a pediatric emergency department without treatment. Ann Emerg Med 1986;15:717-720.

15. Wartman SA, Taggart MP, Palm E. Emergency room leavers. J Community Health 1984;9:261-268.

16. Weissberg MP, Heitner M, Lowenstein SR, et al. Patients who leave without being seen. Ann Emerg Med 1986;15:813-817.

17. Hickey L, Hawton K, Fagg J, et al. Deliberate self-harm patients who leave the accident and emergency department without a psychiatric assessment. J Psychosom Res 2001;50:87-93.

18. Hobbs D, Kunzman SC, Tandberg D, et al. Hospital factors associated with emergency center patients leaving without being seen. Am J Emerg Med 2000;18:767-772.

19. Lombardi G, Elsner N, Gennis P, et al. Effect of periodic waiting time announcements on patient walk-outs in a municipal hospital ED [abstract]. Acad Emerg Med 1995;2:434.

20. Fernandes CM, Price A, Christenson JM. Does reduced length of stay decrease the number of emergency department patients who leave without seeing a physician? J Emerg Med 1997;15:397-399.

21. Fernandes CM, Christenson JM. Use of continuous quality improvement to facilitate patient flow through the triage and fast-track areas of an emergency department. J Emerg Med 1995;13:847-855.

22. Fernandes CM, Christenson JM, Price A. Continuous quality improvement reduces length of stay for fast-track patients in an emergency department. Acad Emerg Med 1996;3:258-263.

RELATED ARTICLE: Key Points

* Increases in emergency department volume are mirrored by rising numbers and rates of patients leaving without treatment.

* There may be a threshold of higher acuity patients that can be managed by a single attending physician before other patients decide to leave without treatment.

* Strategies implemented at larger institutions to address the issue of patients leaving without treatment may not be feasible in smaller departments.

Jason T. McMullan, MS-IV, and Frederick H. Veser, MD

From the College of Medicine and Department of Emergency Medicine, Medical University of South Carolina, Charleston, SC.

Reprint requests to Frederick H. Veser, MD, MUSC Dept. of Emergency Medicine, PO Box 250300, Charleston, SC 29425.