A method for converting injury severity in NASS93 (AIS90) to NASS88 (AIS85)
Garthe, Elizabeth A.; Ferguson, Susan A.; Early, Nancy
Proceedings of 40th Annual Conference of the Association for the Advancement of Automotive Medicine
For the 1993 calendar year the National Highway Traffic Safety Administration (NHTSA) National Accident Sampling System (NASS) used the Association for the Advancement of Automotive Medicine's (AAAM's) Abbreviated Injury Scale, 1990 Revision (AIS90) to code motor vehicle injury severity. Between 1987 and 1992, NASS used the AIS 1985 Revision (AIS85) to code injury severity. The 1990 revision of AIS resulted in substantial changes in the way injuries are coded compared with AIS85. The result is that AIS90 has a higher proportion of injuries in less severe categories than the AIS85 version. In this paper a severity conversion method in which NASS 1993 and later injury codes are assigned AIS85 seventies, is presented. Because of the substantial differences between AIS85 and AIS90, researchers are cautioned against combining data from these two coding systems without first applying the conversion.
Comparisons of the thoracic trauma index with other models
Shaibani, Saami J.; Baum, Herbert M.
Accident Analysis and Prevention
The thoracic trauma index (TTI) provides an indication of the severity of injuries received by motor vehicle occupants in side-impact collision environments. The index was derived from results on two sets of cadaver tests. Using a variety of statistical and numerical methods, the authors reanalyzed the data from these 80+ cadaver tests to construct a better measure of injury than TTI. Indices generated by these analyses were compared with TTI using the following quantitative measures: monotonicity, overlap, percentage correct, and sensitivity. The values of these measures are broadly similar for all indices and none of the new indices consistently performs better than TTI. This suggests that TTI is as good a predictor of injury as any of the several alternative models created.
Injury classification and the international classification of diseases codes
Baker, Susan P.
Accident Analysis and Prevention
Improvements in the widely used International Classification of Diseases (ICD) are important to our ability to study and prevent injuries. ICD “N codes” would be far more useful if they provided more detail, especially for internal injuries, and if they were modified to facilitate conversion to the Abbreviated Injury Score (AIS). A modular system for ICD “E” codes should include the etiologic agent, vector or vehicle, event or circumstances, and intent.
Methodological considerations in the use of the abbreviated injury scale in trauma epidemiology
Barancik, Jerome I.; Chatterjee, Barbara F.
The Journal of Trauma
As part of an incidence study of external cause-specific trauma, the Abbreviated Injury Scale (AIS) and the Injury Severity Score (ISS) are being used to measure the severity of the anatomic injuries. Problems identified in the study pilot phase by medical record specialists, after training in AIS procedures, include noteworthy variations in the interpretation of scaling procedures in the AIS dictionary. The AIS dictionary was replaced by a newly designed single page (SP) precoded abstracting form. It contains alphabetical descriptors for each trauma type within a body region and a unique 3-digit identifier assigned to each. The AIS severity codes are not mentioned on the form. Abstractors are instructed to code all injuries for an episode. A computer algorithm has been developed and implemented to assign the AIS severity codes. Accuracy and precision improved markedly by eliminating the need to make severity scoring decisions during the AIS coding process.
Indexes of severity: underlying concepts -- a reply
O'Neill, Brian; Zador, Paul L.; Baker, Susan P.
Health Services Research
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. Most of the objections apparently stem from fundamental confusion concerning the use of such indexes. 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.
The injury severity score: an update
Baker, Susan P.; O'Neill, Brian
The Journal of Trauma
The Injury Severity Score is a method for numerically describing the overall severity of injury. It can be applied to persons who have sustained injury to more than one area of the body as well as to those with isolated injuries. An individual’s Injury Severity Score (ISS) is determined by rating each injury with the Abbreviated Injury Scale (AIS), then adding together the squares of the highest AIS rating for each of the three most severely injured body areas. The ISS correlates substantially better with mortality than does the AIS rating for the single most severe injury (1). First published in the Journal of Trauma in 1974 (1), the original results have been verified by other investigators (2, 6) and the method is now recommended by an inter-organizational committee on injury scaling for use in connection with the widely used AIS (4). This update summarizes recently adopted, major changes in the AIS and some recent research confirming the validity of the Injury Severity Score and extending its potential usefulness.
The abbreviated injury scale and injury scale and injury severity: new developments
Baker, Susan P.
Insurance Institute for Highway Safety
A century ago, Sir Francis Galton wrote a paper called "Statistical Inquiries into the Efficacy of Prayer.” He managed to cast substantial doubt on the efficacy of prayer -- for example, by pointing to the short life span of many British kings for whom millions of people had prayed every Sunday. More recently, David Boyd showed us a statistical analysis of death rates at three kinds of hospitals in Illinois. Trauma death rates were substantially higher in the regional trauma centers -- about 7 percent, compared to 4 percent in the other hospitals -- an observation that might well have led a skeptic like Sir Francis to question the efficacy of medical care at trauma centers. All of us, of course, realize that these results would be expected when critically injured patients go to major trauma centers while ones with less serious injuries go to smaller hospitals. The problem is to determine whether patients with similar injuries fare better at major trauma centers than in the average hospital: To do that requires the ability to categorize patients on the basis of the severity of their injuries. Therefore I would like to briefly describe recent developments in two research tools for describing injury severity -- the Abbreviated Injury scale and the Injury Severity Score.
The injury severity score: a method for describing patients with multiple injuries and evaluating emergency care
Baker, Susan P.; O'Neill, Brian; Haddon, William Jr.; Long, William B.
The Journal of Trauma
A method for comparing death rates of groups of injured persons was developed, using hospital and medical examiner data for more than two thousand persons. The first step was determination of the extent to which injury severity as rated by the Abbreviated Injury Scale correlates with patient survival. Substantial correlation was demonstrated. Controlling for severity of the primary injury made it possible to measure the effect on mortality of additional injuries. Injuries that in themselves would not normally be life-threatening were shown to have a marked effect on mortality when they occurred in combination with other injuries. An Injury Severity Score was developed that correlates well with survival and provides a numerical description of the overall severity of injury for patients with multiple trauma. Results of this investigation indicate that the Injury Severity Score represents an important step in solving the problem of summarizing injury severity, especially in patients with multiple trauma.
The injury severity score: development and potential usefulness.
Baker, Susan P; O'Neill, Brian; Haddon, William Jr.; Long, William B.
Proceedings of the 18th Annual Conference of the American Association for Automotive Medicine
A method for comparing death rates of groups of injured persons was developed, using hospital and medical examiner data for more than two thousand persons. The first step was determination of the extent to which injury severity as rated by the Abbreviated Injury Scale correlates with patient survival. Substantial correlation was demonstrated. Controlling for severity of the primary injury made it possible to measure the effect on mortality of additional injuries. Injuries that in themselves would not normally be life-threatening were shown to have a marked effect on mortality when they occurred in combination with other injuries. An Injury Severity Score was developed that correlates well with survival and provides a numerical description of the overall severity of injury for patients with multiple trauma.