title: Recent trends in violence-related behaviors among high school students in the United States.
abstract: BACKGROUND
  Violence-related behaviors such as fighting and weapon carrying are associated with serious physical and psychosocial consequences for adolescents.
  
  
  OBJECTIVE
  To measure trends in nonfatal violent behaviors among adolescents in the United States between 1991 and 1997.
  
  
  METHODS
  Nationally representative data from the 1991, 1993, 1995, and 1997 Youth Risk Behavior Surveys were analyzed to describe the percentage of students in grades 9 through 12 who engaged in behaviors related to violence. Overall response rates for each of these years were 68%, 70%, 60%, and 69%, respectively. To assess the statistical significance of time trends for these variables, logistic regression analyses were conducted that controlled for sex, grade, and race or ethnicity and simultaneously assessed linear and higher-order effects.
  
  
  METHODS
  Self-reported weapon carrying, physical fighting, fighting-related injuries, feeling unsafe, and damaged or stolen property.
  
  
  RESULTS
  Between 1991 and 1997, the percentage of students in a physical fight decreased 14%, from 42.5% (95% confidence interval [CI], 40.1%-44.9%) to 36.6% (95% CI, 34.6%-38.6%); the percentage of students injured in a physical fight decreased 20%, from 4.4% (95% CI, 3.6%-5.2%) to 3.5% (95% CI, 2.9%-4.1%); and the percentage of students who carried a weapon decreased 30%, from 26.1% (95% CI, 23.8%-28.4%) to 18.3% (95% CI, 16.5%-20.1%). Between 1993 and 1997, the percentage of students who carried a gun decreased 25%, from 7.9% (95% CI, 6.6%-9.2%) to 5.9% (95% CI, 5.1%-6.7%); the percentage of students in a physical fight on school property decreased 9%, from 16.2% (95% CI, 15.0%-17.4%) to 14.8% (95% CI, 13.5%-16.1 %); and the percentage of students who carried a weapon on school property decreased 28%, from 11.8% (95% CI, 10.4%-13.2%) to 8.5% (95% CI, 7.0%-10.0%). All of these changes represent significant linear decreases.
  
  
  CONCLUSIONS
  Declines in fighting and weapon carrying among US adolescents between 1991 and 1997 are encouraging and consistent with declines in homicide, nonfatal victimization, and school crime rates. Further research should explore why behaviors related to interpersonal violence are decreasing and what types of interventions are most effective.
authors.affiliation: Division of Adolescent and School Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA. nad1@cdc.gov
authors.forename: N D
authors.initials: ND
authors.lastname: Brener
authors.forename: T R
authors.initials: TR
authors.lastname: Simon
authors.forename: E G
authors.initials: EG
authors.lastname: Krug
authors.forename: R
authors.initials: R
authors.lastname: Lowry
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D005006:Ethnicity; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D012574:Schools / Q000706:statistics & numerical data* / Q000639:trends; D014481:United States / Q000453:epidemiology; D014754:Violence / Q000706:statistics & numerical data* / Q000639:trends