To the Editor: The introduction of a medical emergency team (MET) at the Austin Hospital significantly reduced cardiac arrest and deaths, and reduced time spent by survivors of cardiac arrest in the intensive care unit (ICU) and in hospital.1

We note that the evaluation of the MET was preceded by a 12-month period of education and a 2-month “run-in” period before the effects of the MET were analysed. We would be interested to know the incidence of death and cardiac arrest, and the duration of ICU and hospital admission in survivors of cardiac arrest during these two periods.

Another MET service also claimed substantial benefits in patient outcomes,2 but was criticised on the basis that the results may have been due to better education of ward staff in recognising the antecedent signs of cardiac arrest and/or the creation of more “do-not-resuscitate” orders.3 While the latter criticism cannot be levelled at the study by Bellomo et al, no attempt is made to separate out the effects of the lengthy education period and the operation of the MET. This is a pity, because it would have been a relatively simple matter to do so without detracting from the obvious benefit of the service.

Why was a 2-month “run-in” period between education and operation of the MET allowed before analysis of results? Was this a post-hoc decision or were there foreseeable difficulties during the introduction of the MET?

Did patient outcomes change during these two periods compared with the period before the MET?

In reply: Tibballs and Kinney raise important questions about our trial of a medical emergency team (MET).1 My colleagues and I are, in fact, currently studying these issues.

Preliminary (not fully double-checked) data show that during the education period there were 69 cardiac arrests — an average of 23 cardiac arrests per 4-month block. This is a clear reduction from the 63 recorded during the 4-month control period and similar to the 22 cardiac arrests reported during the 4-month MET period.

These 69 cardiac arrests led to a total of 227 intensive care unit bed-days or a 75 bed-day average for each 4-month block, about 50% of the number recorded during the control period, but more than twice as many as during the MET period. These patients remained in hospital for a total of 986 hospital bed-days or 328 days per 4-month block, close to an 80% reduction compared with our control period, and twice as many as the number achieved during the MET period. Unfortunately, although we are pursuing mortality data, we won’t be able to provide them for another 6 months because of a changeover in the computer system at our hospital. Tibballs and Kinney are invited to contact me directly by mid-2004.

The 2-month run-in period was chosen prospectively, as we expected that the uptake of the MET (a major change of culture) might be slow and require time and encouragement. We were wrong: the MET was taken up with zest and enthusiasm. The histogram (Box 4) in our article1 shows no cardiac arrests during the run-in period, not because they were not recorded, but because there were literally none for 2 months in a row! Obviously, there were also no post-cardiac-arrest bed-days. Again, mortality figures for this period should be available by mid-2004.

As we stated in the Discussion of our article, the educational program associated with the MET may indeed have been partly responsible for the findings. We were careful at all times to say that introducing the MET was effective, not the MET per se (see Conclusion).1

We are not aware of any prospective studies testing the effectiveness of introducing a hospital-wide education program aimed at increasing awareness of the significance of physiological instability. Our findings support a powerfully beneficial role of education, but only represent a post-hoc analysis and require validation in other settings and institutions. The role of education was prospectively and separately investigated in the recently completed multicentre cluster-randomisation MERIT study (Medical Early Response Intervention and Therapy). Its results should be available in the second half of this year.