The effect of multidisciplinary case management on selected outcomes for frequent attenders at an emergency department

People who frequently attend hospital emergency departments (ED) are a vulnerable population, with a high burden of disease,1,2 increased mortality rates, and a greater risk of death from violent causes including suicide and alcohol or drug misuse.3 Frequent attenders are characterised by poverty and homelessness, as well as psychiatric illness, drug and alcohol use, and chronic medical conditions.4-6 As frequent, chaotic and episodic users of health services,7,8 including multiple EDs,9 they are difficult to engage in long-term care.10

There is a belief that these people use health services excessively and that their ED utilisation is often inappropriate and unnecessary.11 In several countries, attempts to divert frequent attenders from EDs and reduce “unnecessary” ED attendances have met with varying results. Neither education of patients12 nor management care plans13 have altered the frequency of ED attendance. The most effective diversion strategies adopted multidisciplinary approaches, including social-work support.14,15 The limited Australian research on this topic suggests that the majority of frequent attenders are not suitable for diversion to general practice.16

In 2000, the Victorian Government introduced the Hospital Admission Risk Program to address the demand for hospital services.17 Under this program, St Vincent’s Hospital in Melbourne established the Assessment, Liaison and Early Referral Team (ALERT) in 2001 — an ED-based, multidisciplinary case management (CM) service, providing care to people with complex needs, including frequent attenders. Given that similar multidisciplinary approaches in other countries reduced ED use and improved psychosocial outcomes for a similar population, we aimed to evaluate the effect of ED-initiated, multidisciplinary CM on hospital utilisation patterns and psychosocial factors for frequent attenders at an Australian ED.

A retrospective cohort analysis was conducted in which the study population of frequent ED attenders provided its own historical controls. The setting was St Vincent’s Hospital, Melbourne (SVHM), an inner metropolitan tertiary hospital with an annual ED attendance of 32 000 adults. A 24-month study period was set for each patient between 1 January 2000 and 31 December 2004, consisting of 12 months before and after commencing ED-initiated CM. ED attendance dates for the study population at the only other two adult, general, public hospitals located within 5 km of SVHM were obtained.

Our study has shown that implementation of ED-based multidisciplinary CM resulted in a trend towards increased utilisation of ED services, especially overnight stays, for frequent ED users. The study also provides evidence that CM improves psychosocial factors for frequent attenders, in particular housing status and linkage with general practice and community services.

A randomised controlled trial of multidisciplinary CM in the United States,13 which included use of patient care plans but no social worker involvement or patient consent, failed to show a change in ED visits by frequent attenders. In Europe, social-work intervention reduced ED visits by frequent attenders,2 while generally, other models of multidisciplinary CM have been shown to be effective clinically and costwise.21 In the US, Okin et al found that ED-initiated, multidisciplinary CM for frequent attenders decreased ED use and improved psychosocial status while saving costs.14 Pope et al in Canada found that intensive CM of a small number of frequent attenders reduced ED visits.15 Both studies were prospective, required consent and used the patients as their own historical controls. In our study, retrospective analysis allowed us to include patients (those who were intoxicated, confused or psychotic) whose ability to consent in a prospective study would have been impaired. This, in itself, may account for the different findings of our study compared with those in other countries.

In another Australian study of ED-based care coordination funded by the Hospital Admission Risk Program,22 hospital admission rates fell but ED re-presentation rates were unaltered; there were no controls and frequent attenders were not targeted.

Our different results may also be explained by the diagnostic profile of our patients: 73% had either substance misuse or psychosocial issues as their primary problem, and only 27% had chronic medical problems. Moss et al had only 12% of patients with substance misuse or psychosocial problems,22 and two other studies5,8 reported 51% and 55% of patients with chronic medical problems.

We found that an increase in primary care linkage and engagement does not appear to alter the pattern of ED use for frequent attenders, despite expectations that it should. Our findings support previous research1,7 showing that frequent attenders use multiple health services heavily but availability of primary care does not alter ED use.

Our study has a number of limitations. Although most similar research has used the 12 months before and after framework, this may not allow sufficient time to observe outcomes for patients with complex needs. Furthermore, the CM model may have varied over time with the changeover of clinicians, and evolution of the ALERT program over the study period may have affected outcomes.

Retrospective analyses are subject to more bias than prospective studies. For our study, quantitative data were complete and objective and thus sufficiently robust for statistical analysis. We minimised reporter bias with clearly written guidelines for psychosocial scoring, collaborative scoring, and inter-rater reliability testing.

The before-test – after-test study design, using patients as their own historical controls, is limited by what happens to patients over time. Hospital utilisation patterns may have changed not as a result of CM, but because of illness progression or other factors, such as a geographic change of residence. Although ED use for some frequent attenders decreases over time, others (those with mental illness or substance misuse) evince sustained heavy use of multiple EDs over a number of years.8

Sample selection is open to bias. Given the unique characteristics of the frequent attenders receiving ALERT CM, it was impossible to compare them with other frequent attenders or with a matched control group. Most frequent attenders not picked up for ALERT CM were receiving psychiatric CM and thus were unsuitable for comparison. While our study population was complex (and previously difficult to engage in services), it was this type of patient that we wished to study.

From an emergency demand reduction perspective, CM appears to have the opposite of the desired effect; however, frequent attenders comprise a small proportion of the ALERT program. From the program’s own analysis of all patients receiving ALERT CM care, except frequent attenders, ALERT CM results in expected outcomes of reduced hospital utilisation (unpublished data — Hospital Admission Risk Program Evaluation Document. SVHM ALERT/HiT H02-190. Six-month report to the Department of Human Services, July–December 2004).

Beliefs that ED use by frequent attenders is inappropriate and should be reduced are not substantiated; expectations that they can be diverted from the ED by CM are questionable. ALERT clinicians interpret the trend towards increased ED presentation after CM in a positive light, as these patients, previously very difficult to engage in any service, are now showing a tendency to engage. Some of the time taken to deliver this service occurs in the ED and hence increases ED utilisation. From a patient perspective, it may be desirable for frequent attenders to present to the ED more often, so their complex health needs can be addressed.

Arguably, EDs are among the most appropriate places for this population to access acute medical care, offering 24-hour services without exclusion criteria, no monetary charge, and a safe environment with high levels of medical, nursing and allied health resources. Dent et al have shown, for an inner urban ED, that attendances of people who present most frequently are appropriate, and these people are unsuitable for general practice diversion.16

Since attempted diversion has no proven patient benefit, EDs should be wary of assumptions about inappropriate or unnecessary use of ED services. EDs are well placed for delivery of care to vulnerable and complex patients, and should be resourced to facilitate this.

The improvement in psychosocial factors as a result of CM has longer-term implications for health outcomes that may not manifest or be measurable in the short term.23 The challenge for the future is to measure longer-term outcomes for frequent attenders, particularly links between psychosocial improvements and health status, including ED utilisation. Additionally, more qualitative research into the lives of frequent attenders would provide valuable insights into this complex and unique population.

5 Psychosocial scores for all frequent attenders before and after case management (CM) (n = 60)

A: Housing status, primary care, and community care engagement

B: Statistical analysis of social scores for housing status, substance use, primary care and community care engagement

	Housing status (mean score)			Drug and alcohol use (% positive)			Primary care engagement (mean score)			Community care engagement (mean score)
Population	Before CM	After CM	Z, P	Before CM	After CM	P	Before CM	After CM	Z, P	Before CM	After CM	Z, P
Whole group	3.6	4.1	− 2.681, 0.007	68.3%	58.9%	0.1	2.6	3.1	− 2.971, 0.003	2.1	3.2	− 5.086, < 0.001
Subgroups
General medical	4.2	4.6	− 1.633, 0.1	31.3%	12.5%	0.3	3.2	3.6	− 1.276, 0.2	2.3	3.5	− 2.994, 0.003
Drug and alcohol	3.0	3.4	− 1.981, 0.048	100%	92.0%	0.5	2.1	2.7	− 2.401, 0.016	1.9	2.9	− 3.213, 0.001
Psychosocial	3.9	4.5	− 1.134, 0.3	55.6%	53.3%	1.0	2.8	3.3	− 1.492, 0.1	2.3	3.2	− 2.658, 0.008
CM = case management.