Introduction of medical emergency teams in Australia and New Zealand: a multi-centre study

Abstract

Introduction: Information about Medical Emergency Teams (METs) in Australia and New Zealand (ANZ) is limited to local studies and a cluster randomised controlled trial (the Medical Emergency Response and Intervention Trial [MERIT]). Thus, we sought to describe the timing of the introduction of METs into ANZ hospitals relative to relevant publications and to assess changes in the incidence and rate of intensive care unit (ICU) admissions due to a ward cardiac arrest (CA) and ICU readmissions.

Methods: We used the Australian and New Zealand Intensive Care Society database to obtain the study data. We related MET introduction to publications about adverse events and MET services. We compared the incidence and rate of readmissions and admitted CAs from wards before and after the introduction of an MET. Finally, we identified hospitals without an MET system which had contributed to the database for at least two years from 2002 to 2005 and measured the incidence of adverse events from the first year of contribution to the second.

Results: The MET status was known for 131 of the 172 (76.2%) hospitals that did not participate in the MERIT study. Among these hospitals, 110 (64.1%) had introduced an MET service by 2005. In the 79 hospitals in which the MET commencement date was known, 75% had introduced an MET by May 2002. Of the 110 hospitals in which an MET service was introduced, 24 (21.8%) contributed continuous data in the year before and after the known commencement date. In these hospitals, the mean incidence of CAs admitted to the ICU from the wards changed from 6.33 per year before to 5.04 per year in the year after the MET service began (difference of 1.29 per year, 95% confidence interval [CI] -0.09 to 2.67; P = 0.0244). The incidence of ICU readmissions and the mortality for both ICU-admitted CAs from wards and ICU readmissions did not change. Data were available to calculate the change in ICU admissions due to ward CAs for 16 of 62 (25.8%) hospitals without an MET system. In these hospitals, admissions to the ICU after a ward CA decreased from 5.0 per year in the first year of data contribution to 4.2 per year in the following year (difference of 0.8 per year, 95% CI -0.81 to 3.49; P = 0.3).

Conclusion: Approximately 60% of hospitals in ANZ with an ICU report having an MET service. Most introduced the MET service early and in association with literature related to adverse events. Although available in only a quarter of hospitals, temporal trends suggest an overall decrease in the incidence of ward CAs admitted to the ICU in MET as well as non-MET hospitals.

Figure 1

Flow diagram of the Medical Emergency Team (MET) status of 172 hospitals in Australian and New Zealand with intensive care units. The diagram does not include hospitals participating in the Medical Emergency Response and Intervention Trial. ANZICS-APD, Australian and New Zealand Intensive Care Society Adult Patient Database.

Figure 2

Uptake of Medical Emergency Team (MET) services into those hospitals in Australia and New Zealand for which the MET status is known. Each data point represents the cumulative total of MET services commenced (y-axis) at the corresponding time (x-axis). The commencement of the MET service at Liverpool Hospital (University of New South Wales, Sydney, Australia) (June 1989) is omitted for the purpose of presentation. Shown below the x-axis are the first authors of publications related to adverse events and METs: Lee, et al. [4]; McQuillan, etal. [16]; Smith and Wood [17]; Buist, et al. [14]; Goldhill, et al. [15]; Bristow, et al. [13]; Buist, et al. [6]; Hodgetts [21]; Foraida [22]; Bellomo, et al. [5]; and DeVita [7].

Figure 3

Uptake of Medical Emergency Team (MET) services into various categories of hospitals in Australia and New Zealand for which the MET status is known. Each data point represents the cumulative total of the number of MET services commenced (y-axis) at the corresponding time (x-axis). The commencement of the MET service at Liverpool Hospital (University of New South Wales, Sydney, Australia) (June 1989) is omitted for the purpose of presentation. Shown below the x-axis are the first authors of publications related to adverse events and METs: Lee, et al. [4]; McQuillan, et al. [16]; Smith and Wood [17]; Buist, et al. [14]; Goldhill, et al. [8]; Bristow, et al. [13]; Buist, et al. [6]; Hodgetts [21]; Foraida [22]; Bellomo, et al. [5]; and DeVita [7].