title: Classification tree analysis of the factors influencing injury-related disability caused by the Wenchuan earthquake.
abstract: OBJECTIVE
  To identify the factors that influenced the risk of injury-related disability caused by the Wenchuan earthquake.
  
  
  METHODS
  A chi-squared automatic interaction detection (CHAID) classification tree analysis was used to retrospectively analyse clinical data from patients who underwent surgical treatment for earthquake-related injuries in the first 5 days after the earthquake. The CHAID classification tree explored the relationships between the development of disability and potential influencing factors including sex, age, time interval between injury and treatment, wound type, preoperative and postoperative haemoglobin levels, and operation time.
  
  
  RESULTS
  A total of 334 patients underwent surgery; of these, 113 (33.8%) were discharged with varying degrees of permanent disability. The CHAID classification tree showed that children (≤ 17 years old), a long time interval between injury and treatment, an open wound and a low preoperative haemoglobin level were significant risk factors for disability.
  
  
  CONCLUSIONS
  The results of this study can help to stratify patients according to their medical needs and to help allocate the available resources efficiently to ensure the best outcomes for injured patients during future earthquakes.
authors: Department of Social Medicine, School of Public Health, Sichuan University, Chengdu, Sichuan Province, China.
authors: Xiang
authors: X
authors: Liu
authors: Yuan-Yuan
authors: YY
authors: Liu
authors: Si-Huan
authors: SH
authors: Liu
authors: Xiang-Rong
authors: XR
authors: Zhang
authors: Lei
authors: L
authors: Du
authors: Wen-Xia
authors: WX
authors: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004185:Disability Evaluation; D055866:Earthquakes / Q000706:statistics & numerical data*; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D014947:Wounds and Injuries / Q000453:epidemiology* / Q000601:surgery*; D055815:Young Adult
chemical_list: D006454:Hemoglobins
keywords: CHAID; Earthquake; chi-squared automatic interaction detection; classification tree; disability; injury; surgery