Whilst most hospital admissions in older people from the ED are clinically appropriate, a minority are considered avoidable for want of multidisciplinary physician, nursing and allied health care that facilitates safe discharge and management in the community [5]. The clinical risks associated with hospitalisation of older people are well documented including deconditioning, functional decline, delirium and iatrogenic illness [6,7]. There are also potential benefits in terms of cost savings and improved patient satisfaction through avoiding hospital admission [8]. Several prior non-experimental studies have reported favourable results from the use of geriatric services, including allied health staff, to facilitate discharge from the ED [9-11]. Patients are predominantly referred to these services after ED assessment has deemed the patient potentially suitable for discharge, in other words the services are seen as enablers to assist discharge in patients deemed medically suitable for such.

Patients aged 65 and over presenting to the ED with one or more from a list of ten presenting medical complaints were included (Table ​(Table1).1). These diagnoses were selected on the basis of a prior audit of hospital statistics showing they were common ED presenting problems with a high rate of admission and substantial use of allied health resources as an inpatient.

Eligibility and enrolment procedures for the study are summarised in Figure ​Figure1.1. Patients were screened early after triage on the basis of age and clinical presentation. Patients requiring immediate resuscitation, triage to a critical care bay in the ED or other urgent medical input were excluded.

The CCT were designed as exclusively ED based teams, functioning autonomously with a brief to facilitate safe early discharge to home of older people. In particular, they focussed on overcoming barriers to safe discharge whether they are related to the presenting problem (e.g. mobility post fall) or not (e.g. isolated unsupervised living arrangements in a patient with low grade cardiac failure). The CCT operated similarly at each site, teams were encouraged to select patients for assessment and intervention rather than wait for referral from other ED staff. Thus, team assessment occurred in parallel to ED medical staff assessment so that team input into disposition decisions for the patient could be incorporated into the final medical decision, always made by the treating ED physician, as to whether patient admission to hospital from ED was required. Each CCT contained at least one physiotherapist, occupational therapist and social worker with extensive geriatric experience. Physician (usually a geriatrician or geriatric trainee), nursing and other allied health staff such as speech therapists were co-opted to assist the teams as required. CCT were present in the ED seven days per week for a minimum of 10 h per day, but never between the hours of 2200 and 0600.

Intervention patients underwent comprehensive functional assessment by at least one CCT member, followed by the initiation of services to address any needs identified on assessment. The assessment incorporated components of previously validated instruments, modified after CCT input, for assessing factors such as discharge needs, falls risk, activities of daily living and cognition [12-14]. Control patients were eligible for CCT assessment but did not receive such before a decision to admit or discharge the patient was made.

Research assistants employed specifically for the study prospectively collected clinical data on intervention and control patients. Patient demographics, time of arrival and triage urgency were obtained from the Emergency Department Information System (EDIS)^®. Admission to hospital was defined by an electronic bed request for admission to an inpatient ward bed including the ED observation ward. Deaths in the ED were included as admissions. Data were entered and stored electronically in SPSS^® version 17 (Chicago, IL, USA).

The study outcome was proportion of admissions to hospital from the ED. The intervention and control groups were compared on a univariate basis using Pearson's chi square test. Due to the non-randomized nature of the study, we used propensity score matching to stratify the likelihood of having been seen by CCT based on the presenting medical problem as well as potential confounders of gender, age, living arrangements, triage urgency, time of arrival to the ED, study site and comorbidities. Propensity scores provide a means for adjusting for bias in non-randomised studies of causal effects [15]. Effect modification (statistical interaction) was tested for and not found amongst the variables. The probability, based on their propensity score, of a patient being assigned to the intervention group was used in a nearest neighbour method to match intervention and control patients. Admission rates in the intervention and control groups were then compared using conditional logistic regression. A p value of 0.05 was used as the threshold for statistical significance. Pre-planned subgroup analysis on the basis of individual diagnoses, and logical groupings of diagnoses, was performed using binary logistic regression models adjusting for the potential confounders listed.

Tables ​Tables44 and ​and55 contain the adjusted OR for each individual condition and conditions combined into logical groupings. A beneficial CCT effect is seen with angina and musculoskeletal conditions, but no other diagnoses.

A number of studies have evaluated programs to look at ED discharge, largely from the perspective of reducing post-discharge risk. We are not aware of any study that has looked specifically at the impact of allied health staff on the admission decision. Enhanced identification of an at- risk discharged group and referral of that group to community care givers had some benefit in reducing short term functional decline post discharge [16]. More comprehensive geriatric assessment by additional care providers outside the primary care physician have shown conflicting results but have also found benefit on functional status [17], but not necessarily ED usage [18].

It appears that the benefit of CCT intervention on admission reduction is confined to musculoskeletal conditions such as back pain (OR 0.56) and lower limb pain (OR 0.63); or to conditions likely to be episodic and resolved by the time the patient has arrived in ED such as angina (OR 0.71). Our study shows no benefit accrues from CCT intervention in medical conditions with ongoing significant symptoms such as pneumonia, cardiac failure and delirium. Though these findings are robust, any subgroup analysis should be interpreted with caution due to the possibility of type II error. We had hypothesised that CCT input would reduce admission rates across all of the selected conditions studied. The lack of any intervention effect in conditions such as pneumonia or cardiac failure shows that almost all patients with these conditions presenting to ED are admitted, and that discharge of such patients is not enhanced by CCT input. The underlying medical condition of the patient rather than unmet community or functional needs is presumably more influential in the decision to admit in these subgroups. This has implications for workforce deployment; CCT like services should concentrate resources on patient groups where they are likely to produce a beneficial reduction in admission rather than those where admission rates are unchanged by their input.

We have confirmed that admission rates in the older ED patient are high. With population ageing a worldwide phenomenon, measures to safely reduce hospital admission rates in patients presenting to an ED are important in the quest to maximise efficient use of scarce inpatient beds. Even small changes in admission rates at the front door will result in meaningful reductions in hospital occupancy and improve system capacity. The use of allied health personnel working as a CCT in ED appears to support this aim.

In our study we included ED observation unit patients as admitted patients. Such patients typically have brief admissions of less than 24 h though there is evidence that at least 15% of such patients need longer inpatient stays [19]. By including short stay observation unit stays in the same group as inpatient admissions, we may have missed an additional benefit of CCT intervention if CCT increased the proportion of admissions that are observation unit admissions as opposed to ward admissions, where there is typically a longer length of stay. This was not part of our original hypothesis and so not analysed, but would be worthy of future research.

We have concentrated on admission avoidance, underpinned by an assumption of the clinical, economic and qualitative benefits of avoiding hospitalisation in carefully selected older patients. However, there are also risks involved with the discharge of older people from the ED - early functional decline, re-presentation and unanticipated death are all described [20-22]. In fact, other researchers have similarly used geriatric teams in ED to prevent inappropriate ED discharge [23]. The nature of a community's support services, the capacity of these services to consistently respond to referrals and the hospital's appetite for risk at point of discharge will all influence whether a patient is sent home from the ED. The decision to discharge or admit an older person, therefore, is sometimes a fine balance between the feasibility, risks and benefits of discharge.

Our study is noteworthy because we used assessment by CCT soon after arrival in the ED, before a decision on the disposition of the patient had been made, to assess the impact of early intervention on discharge rates. We did not attempt to assess the outcome of patients following discharge. Post discharge outcomes have been subject to a number of studies summarised in a recent systematic review which found some evidence of improved short term functional outcomes and reduced readmission rates with geriatric intervention at or after discharge [24]. A feature of these trials is that the referral to the geriatric team occurs after the decision to discharge has already been made [17].

In addition to admission avoidance, a number of other clinical benefits are likely to be derived from the location of experienced allied health teams within the ED. Studies have shown the functional needs of older people are often poorly recognised within the ED [25,26]. Communication between the ED and community care providers can be poor [27]. Coordination of care for patients with complex needs post discharge may be enhanced by specific planning [11].