STATISTICAL ASPECTS OF INJURY SEVERITY; PART I: COMPARISON OF TWO POPULATIONS WHEN THERE ARE SEVERAL GRADES OF INJURY; PART II: THE CASE OF SEVERAL POPULATIONS BUT THREE GRADES OF INJURY

A method is proposed of comparing the average levels of injury sustained in two conditions. It consists of plotting the proportion of cases in one population that exceed an arbitrary threshold of severity against the proportion of cases in the other population that exceed the same threshold, as the threshold varies. The further this curve is from the 45 degree line, the greater is the difference in severity between the populations. The precise shape of the curve depends on the particular model considered: two examples are derived from considering the distributions of injury severity, respectively, each to be (i) normally distributed with the same variance, or (ii) exponentially distributed; the means of the distributions differing. A number of applications ot his type of theory are outlined. Those types of accidents in which a high proportion of casualities are killed are usually those in which also a high proportion are seriously injured. This paper is concerned with the quantification of this correlation. In particular, it was found (using British data) that the variation in injury severity in a number of situations can be described by alternations in the exponent of a exponential distribution of severity, with the boundary between slight and serious injury occurring at one-third the distance from the origin of the boundary between serious and fatal injury. /Author/

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  • Corporate Authors:

    Operations Research Society of America

    428 East Preston Street
    Baltimore, MD  USA  21202
  • Authors:
    • Hutchinson, T P
  • Publication Date: 1976-8

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Filing Info

  • Accession Number: 00152377
  • Record Type: Publication
  • Source Agency: National Safety Council Safety Research Info Serv
  • Files: TRIS
  • Created Date: May 31 1977 12:00AM