Health services research
-
A discussion of severity index development is presented in relation to conceptual issues in index definition, analytic issues in index formulation and validation issues in index application. The CHOP index is discussed along with six severity indexes described in an earlier paper dealing with underlying concepts to illustrate the material presented. Replies are provided to specific questions raised in an accompanying paper discussing the Injury Severity Score. This conceptual material is presented to provide a foundation for severity index development, to suggest criteria to be used in their formulation and testing, and to identify analyses that can lead to the successful selection and application of an index for a defined purpose.
-
Health services research · Jan 1979
Evaluation of emergency ambulance characteristics under several criteria.
A methodology and analysis are presented for evaluating response time characteristics of emergency ambulance systems. The methodology is based on a Monte Carlo simulation technique and a heuristic optimal-seeking technique for locating emergency ambulances under several criteria based on response time distribution. Optimization criteria include minimum mean system response time, minimum system fractile response time and minimum level-loaded response time. ⋯ From these results alternative dispatch polices can be evaluated. Complementing the analysis is a presentation of a sensitivity analysis and an analysis of existing ambulance sites. Unique to the methodology is the adaption of the heuristic optimal-seeking technique to include any of the three criteria and the effectiveness of the methodology for analyzing small or large ambulance systems.
-
A recent paper on the concepts underlying six indexes of severity that have been proposed for health services research claimed to identify deficiencies in each. A close examination reveals that the criticisms are generally without substance, and that the claim that the indexes "violate some of the principles implied by their formulation" is in error. ⋯ Two of the indexes in question, the Abbreviated Injury Scale AIS) and the Injury Severity Score (ISS), have been validated and are being used widely both in the United States and elsewhere as the principal descriptors of trauma in motor vehicle crashes. The use of these indexes has contributed significantly to motor vehicle crash research and to the improvements in vehicles and highways that are reducing the trauma resulting from such crashes.