Using a simplified pre-hospital 'MET' score to predict in-hospital care and outcomes

Medical emergency team (MET) activation criteria serve as a predictor of serious adverse events on hospital wards and in the emergency department (ED). We aimed to determine whether in-hospital MET activation criteria would be useful in identifying patients at risk in pre-hospital care.

The data were collected retrospectively from 610 adult patients treated by physician-staffed helicopter emergency medical services. Pre-hospital vital signs were compared with MET activation criteria and scored accordingly to receive a simplified pre-hospital 'MET' score. The primary outcome measure was hospital mortality. The secondary outcome measures were admission to intensive care unit and the length of ED stay, intensive care unit (ICU) stay and hospital stay. The simplified pre-hospital 'MET' score was also compared with Emergency Severity Index (ESI) used as a triage tool in ED.

Higher simplified pre-hospital 'MET' scores were associated with hospital mortality (P<0.001), the need for ICU treatment (P<0.001) and a more urgent ESI class in the ED (P<0.001). Higher simplified pre-hospital 'MET' scores were associated with shorter stay in the ED (P<0.001), longer stay in the ICU (P<0.001) and longer hospital stay (P<0.001). A simplified pre-hospital 'MET' score was an independent predictor for hospital mortality (odds ratio 2.42, confidence interval 1.84 3.18, P<0.001), regardless of age or patient's previous overall physical health classified by American Society of Anesthesiologists physical status classification system.

A simplified pre-hospital 'MET' score is a predictor for patient outcome and could serve as a risk assessment tool for the health care provider on-scene.