Severity Index Methodology Development Research Project: Executive Summary

摘要

As funds available to upgrade and maintain emergency medical services are reduced, the need to evaluate the relative effectiveness of various components of the existing emergency care system becomes critical. An important case-mix adjustment in those evaluations is a measure of illness that would group patients by severity and permit comparisons of emergency system performance across common severity levels. The research reported here has developed and tested a severity index methodology based on multiattribute utility theory. The methodology was developed and tested for evaluating two emergency conditions presenting at the ED - ischemic heart disease and major trauma. Using expert judgements of severity as the basic data input, the methodology produces a severity index which is a set of rules for transforming clinical patient information into a single number representing the severity of that patient's illness. Expert judgments to construct four different types of model for each of the two conditions were elicited from ten different physician panels. Separate panels validated the indexes using actual patient charts. Evidence of valid index performance was produced. The indexes were also compared to existing severity measures with favorable results. The methodology was shown to be transportable, replicable, and based on a theoretically sound foundation.