- Journal club critique
- Open Access
Demonstrating the benefit of medical emergency teams (MET) proves more difficult than anticipated
© BioMed Central Ltd 2006
- Published: 1 March 2006
Hillman K, Chen J, Cretikos M, Bellomo R, Brown D, Doig G, Finfer S, Flabouris A: Introduction of the medical emergency team (MET) system: a cluster-randomised controlled trial. Lancet 2005, 365:2091–2097 .
Patients with cardiac arrests or who die in general wards have often received delayed or inadequate care. Medical emergency teams (METs) are trained medical professionals that respond quickly to a change in a patient's condition based on the premise that early intervention may prevent further deterioration and/or death. We investigated whether implementation of a medical emergency team (MET) system could reduce the incidence of cardiac arrests, unplanned admissions to intensive care units (ICU), and deaths.
Prospective cluster-randomized controlled trial.
Twenty-three hospitals in Australia. All hospitals had > 20,000 admissions per year, an emergency department and ICU, and did not currently have a MET system. Participating hospitals were heterogeneous and ranged from large, urban academic centers to small, community hospitals.
After collecting baseline data over 2 months, hospitals were randomly assigned to receive standardized MET implementation or control. Control hospitals did not receive any education about MET at any time and their cardiac arrest teams continued unchanged. During a 4-month implementation period in MET hospitals, the medical and nursing staff were introduced to MET calling criteria, the need to call quickly if these criteria arose, and how to activate MET. Education methods included lectures, videotapes, booklets, but did not include education on the treatment of critically ill or unstable patients. A list of MET calling criteria were attached to all ID badges and displayed on posters throughout the intervention hospitals. Staff awareness was maintained by use of regular reminders until the first day of the study period. The staff designated to form the MET varied between participating centers because of local circumstances. The study protocol required that the MET to be at least the equivalent of the pre-existing cardiac arrest team and consist of at least one doctor and a nurse from the emergency department or ICU. A 6-month study period followed the 4-month implementation period, during which individual hospitals had the responsibility for maintaining staff awareness.
The primary outcome was a composite index of the incidence (events divided by the number of eligible patients admitted to the hospital during the study period) of: cardiac arrests without a pre-existing do-not-resuscitate (DNR) order; unplanned ICU admissions; and unexpected deaths without a pre-existing DNR order taking place in general wards. Secondary outcomes were the incidence of each of these individual endpoints.
Twelve hospitals were allocated to MET and 11 hospitals to control. Introduction of the MET increased the overall calling incidence for an emergency team (3.1 vs 8.7 per 1000 admissions, p = 0.0001). The MET was called to 30% of patients who fulfilled the calling criteria and who were subsequently admitted to the ICU. During the study, there were no differences in the incidence of the composite primary outcome between the control and MET hospitals (5.86 vs 5.31 per 1000 admissions, p = 0.640), nor were there differences for the individual secondary outcomes (cardiac arrests, 1.64 vs 1.31, p = 0.736; unplanned ICU admissions, 4.68 vs 4.19, p = 0.599; and unexpected deaths, 1.18 vs 1.06, p = 0.752). A reduction in the rate of cardiac arrests (p = 0.003) and unexpected deaths (p = 0.01) was seen from baseline to the study period for both groups combined.
The MET system greatly increases emergency team calling, but does not substantially affect the incidence of cardiac arrest, unplanned ICU admissions, or unexpected death.
Though underpowered, the results of this study provide a reliable basis for the design of future studies. While we cannot definitively say that MET systems improve outcomes, it seems self-evident that the goal of identifying and treating patients early in the course of their illness is preferable to waiting until more serious signs and symptoms have developed. Certainly, at the University of Pittsburgh Medical Center where the MET concept has been implemented for more than five years, there is widespread agreement among the physicians and nurses that this approach saves lives and improves the care of our patients.
- Hillman K, Chen J, Cretikos M, Bellomo R, Brown D, Doig G, Finfer S, Flabouris A: Introduction of the medical emergency team (MET) system: a cluster-randomised controlled trial. Lancet 2005, 365: 2091-2097. 10.1016/S0140-6736(05)66733-5View ArticlePubMedGoogle Scholar
- Bellomo R, Goldsmith D, Uchino S, Buckmaster J, Hart GK, Opdam H, Silvester W, Doolan L, Gutteridge G: A prospective before-and-after trial of a medical emergency team. Med J Aust 2003, 179: 283-287.PubMedGoogle Scholar
- Bristow PJ, Hillman KM, Chey T, Daffurn K, Jacques TC, Norman SL, Bishop GF, Simmons EG: Rates of inhospital arrests, deaths and intensive care admissions: the effect of a medical emergency team. Med J Aust 2000, 173: 236-240.PubMedGoogle Scholar
- Buist MD, Moore GE, Bernard SA, Waxman BP, Anderson JN, Nguyen TV: Effects of a medical emergency team on reduction of incidence of and mortality from unexpected cardiac arrests in hospital: preliminary study. BMJ 2002, 324: 387-390. 10.1136/bmj.324.7334.387PubMed CentralView ArticlePubMedGoogle Scholar
- DeVita MA, Braithwaite RS, Mahidhara R, Stuart S, Foraida M, Simmons RL: Use of medical emergency team responses to reduce hospital cardiopulmonary arrests. Qual Saf Health Care 2004, 13: 251-254. 10.1136/qshc.2003.006585PubMed CentralView ArticlePubMedGoogle Scholar
- Nathens AB, Jurkovich GJ, Cummings P, Rivara FP, Maier RV: The effect of organized systems of trauma care on motor vehicle crash mortality. JAMA 2000, 283: 1990-1994. 10.1001/jama.283.15.1990View ArticlePubMedGoogle Scholar