title: The exponential function transforms the Abbreviated Injury Scale, which both improves accuracy and simplifies scoring.
abstract: OBJECTIVE
  We present here the exponential function which transforms the Abbreviated Injury Scale (AIS). It is called the Exponential Injury Severity Score (EISS), and significantly outperforms the venerable but dated New Injury Severity Score (NISS) and Injury Severity Score (ISS) as a predictor of mortality.
  
  
  METHODS
  The EISS is defined as a change of AIS values by raising each AIS severity score (1-6) by 3 taking a power of AIS minus 2 and then summing the three most severe injuries (i.e., highest AIS), regardless of body regions. EISS values were calculated for every patient in two large independent data sets: 3,911 and 4,129 patients treated during a 6-year period at the Class A tertiary hospitals in China. The power of the EISS to predict mortality was then compared with previously calculated NISS values for the same patients in each of the two data sets.
  
  
  RESULTS
  We found that the EISS is more predictive of survival [Zhejiang: area under the receiver operating characteristic curve (AUC): NISS = 0.932, EISS = 0.949, P = 0.0115; Liaoning: AUC: NISS = 0.924, EISS = 0.942, P = 0.0139]. Moreover, the EISS provides a better fit throughout its entire range of prediction (Hosmer-Lemeshow statistic for Zhejiang: NISS = 21.86, P = 0.0027, EISS = 13.52, P = 0.0604; Liaoning: NISS = 23.27, P = 0.0015, EISS = 15.55, P = 0.0164).
  
  
  CONCLUSIONS
  The EISS may be used as the standard summary measure of human trauma.
authors.affiliation: Department of Emergency Medicine, Affiliated Hospital of Hangzhou Normal University, 126 Wenzhou Road, Gongshu District, Hangzhou, 310015, Zhejiang, People's Republic of China. Wang_Xu@hz.cn.
authors.forename: M D
authors.initials: MD
authors.lastname: Wang
authors.affiliation: Department of Emergency Medicine, Affiliated Hospital of Hangzhou Normal University, 126 Wenzhou Road, Gongshu District, Hangzhou, 310015, Zhejiang, People's Republic of China. Fanwenhui168@163.com.
authors.forename: W H
authors.initials: WH
authors.lastname: Fan
authors.affiliation: Department of Neurosurgery, Affiliated Hospital of Hangzhou Normal University, Hangzhou, 310015, Zhejiang, People's Republic of China. Shihai954@163.com.
authors.forename: W S
authors.initials: WS
authors.lastname: Qiu
authors.affiliation: The College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, People's Republic of China. Zzliang1961@163.com.
authors.forename: Z L
authors.initials: ZL
authors.lastname: Zhang
authors.affiliation: 3rd Ward of Hand Surgery, Fengtian Hospital Affiliated with Shenyang Medical College, Shenyang, 110024, Liaoning, People's Republic of China. 13700000592@163.com.
authors.forename: Y N
authors.initials: YN
authors.lastname: Mo
authors.affiliation: Department of Emergency Medicine, Affiliated Hospital of Hangzhou Normal University, 126 Wenzhou Road, Gongshu District, Hangzhou, 310015, Zhejiang, People's Republic of China. 2357586291@qq.com.
authors.forename: F
authors.initials: F
authors.lastname: Qiu
keywords: Abbreviated Injury Scale; Exponential Injury Severity Score; Injury Severity Score; New Injury Severity Score; Prediction of mortality
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