We are not aware of the use of objective prognostic scores to allocate or refuse critical care resources at present and indeed most research demonstrates the ad hoc nature of admission decision-making [59] . However, if, as is likely, review by experienced critical care physicians is impractical, decision support will be required for the non-critical care specialist. Emergency physicians, for example, had a positive predictive value (PPV) of only 73% in identifying those with a low chance of survival, as opposed to critical care fellows (PPV 83%) and the Mortality Probability Model (MPM 0 ; PPV 86%) [60] .