Critical care outreach teams seem to improve survival to discharge from hospital after discharge from critical care and may reduce the number of readmissions to a significant extent. The activity of the outreach team differs from that of medical emergency teams and patient at risk teams. Critical care outreach teams have developed on an ad hoc basis in England and Wales. They differ widely in composition, ranging from lone consultant nurses to multiprofessional teams, and in their working patterns and activity.10
Some outreach teams follow up patients as described in our study, whereas others attend once patients show early warning criteria (see box). The results of our study are therefore not transferable.
Patients are at increased risk of deterioration during the recovery period after discharge from critical care, attributable to early discharge and residual organ dysfunction.12,13
Both often lead to readmission, which in turn is associated with higher inhospital mortality.13,15
Although we present only a preliminary examination of what can be achieved through fundamental interventions and referrals made by experienced critical care nurses during the recovery period, our findings do provide some evidence that this type of innovation is worth while for patient survival and readmission.
A recent study could detect no change in patterns of readmission after the introduction of a critical care outreach team.16
It is difficult to extrapolate from the report if the operational policy was similar to that described in our study, and although the setting seems similar, a far larger sample was examined. The readmission rate for both study periods was 4.0%, unlike our study, which found a reduction of 12.4% compared with 6.0% after the introduction of the outreach team. A readmission rate of 4.0% is below the national average of 6.3% reported by the Intensive Care National Audit Research Centre, indicating that there was little room for the effect of the outreach team to be shown in terms of readmission.
Survival to discharge from hospital has been determined in medical patients after discharge from critical care.14
These patients were chosen because of the high mortality associated with critical illness. Survival was thought to have been affected by a change in resuscitation status, where seven of the 12 patients who survived critical care had their resuscitation status altered to do not resuscitate. It is unlikely that this applied to our study because survival to discharge improved and it is unlikely that this would have occurred if patients had had their resuscitation status altered. A more unlikely reason is that decisions about not resuscitating were made but that patients then survived to discharge from hospital. Alternatively, the proportion of medical patients differed between the two periods under study, but this was not the case.
Strengths and limitations
Our study design could have confounded the results; before and after studies are retrospective, therefore variables cannot be controlled. In our study a concomitant innovation in the hospital could have produced the same results. Patients were, however, discharged from critical care to different areas of the hospital, and at the time of the study there was no other innovation that could have had an effect on patients. The median predicted probability of mortality was 16.1% compared with 20.4% in the historical cohort. Although this was not statistically significant, part or all of the effect seen might be explained by this difference. Several authors have, however, questioned the ability of the tool to predict mortality and it is currently the subject of further investigation by the Intensive Care National Audit Research Centre. The tool therefore might explain some of the variation in outcome but not all of it.17,18
Before and after studies may also show a lack of equivalence between comparators, and interventions may vary. Both our groups had similar risk factors. These were chosen for their association with mortality and readmission and seemed to be appropriate for the purposes of our study. The interventions undertaken by team members did vary, possibly owing to length of time available for the intervention or the manner in which the intervention was undertaken by the individual and on a particular day. It is unlikely, however, that one individual or one intervention can be associated with the findings. Rather, the combined effect of the interventions seems to have had a beneficial effect on outcomes.
The use of routine audit data, rather than specific data collected for research purposes, may also have produced erroneous results. The database was examined on a random basis for reliability and seemed sound.
Our small sample size increased the risk of a type 2 error, which is much smaller than those used to test the effectiveness of medical emergency teams or the effect on readmission rates.8,9,16
If the innovation described here had not been introduced so hastily, owing to political imperative, we could have conducted a prospective randomised controlled trial. Evidence for innovation in service delivery will always be prone to limitations where evaluation is not undertaken before wholesale application. Policy makers should consider testing health service innovation using cluster randomised controlled trials with the hospital as the sampling unit. An example of this is the medical early response intervention and therapy study currently being undertaken in Australia to assess medical emergency teams.19
What is already known on this topic
The management of patients on the ward at risk of critical illness is suboptimal
Substantial sums have been invested in the development of critical care outreach teams
Outreach teams were hastily created and their effect on readmission to critical care or survival to hospital discharge was unclear
What this study adds
Critical care outreach teams seem to improve survival to discharge from hospital and may reduce readmission rates to critical care