title: Age-within-school-class and adolescent gun-carrying.
abstract: BACKGROUND
  Intentional injuries (suicide and homicide) are a leading causes of morbidity and mortality in the United States. Firearms cause approximately 70% of these fatal intentional injuries. Risk factors associated with gun-carrying in adolescent populations include male gender, smoking, alcohol use, drug use, and number of sexual partners. Current knowledge of these and other risk factors has provided limited benefit because many are no more obvious to the clinician a priori than is the tendency to carry guns. Increasing relative age of a student within school class is an easily measured parameter that has been associated with behavioral problems, absenteeism, negative self-image, and high dropout rates.
  
  
  OBJECTIVE
  To characterize the association between relative student age-within-class and tendency to carry firearms.
  
  
  METHODS
  The Massachusetts Youth Risk Behavior Survey, which collects data on demographic characteristics, risk behaviors, and health outcomes.
  
  
  METHODS
  A randomly selected group of 3153 Massachusetts students in grades 9 through 11.
  
  
  METHODS
  The odds of firearms-carrying comparing older to average-age and younger students.
  
  
  RESULTS
  Using multivariate logistic regression, seven risk factors predicted gun-carrying with statistically significant results: older age-within-class (OR: 2.12; 95% CI: 1.09-4.12), male gender (OR: 4.95; 95% CI: 3.01-8.15), black race (OR: 2.49; 95% CI: 1.20-5.14), gang membership (OR: 7.22; 95% CI: 4.51-11.56), missing school out of concern for safety (OR: 2.50; 95% CI: 1.30-4.80), seeking medical treatment after a fight (OR: 4.47; 95% CI: 2.56-7. 78), and fighting without seeking medical treatment (OR: 5.73; 95% CI: 3.09-10.60).
  
  
  CONCLUSIONS
  Older 9th-, 10th-, and 11th-grade students are more likely than their classmates to carry firearms. This information may prove helpful in identifying high-risk students and targeting prevention strategies.
authors.affiliation: Department of Internal Medicine, Boston University School of Medicine, MA, USA.
authors.forename: D N
authors.initials: DN
authors.lastname: Hayes
authors.forename: D
authors.initials: D
authors.lastname: Hemenway
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000208:ethnology / Q000523:psychology; D000367:Age Factors; D003625:Data Collection; D005239:Fear; D005260:Female; D005389:Firearms / Q000706:statistics & numerical data*; D006801:Humans; D007604:Juvenile Delinquency; D016015:Logistic Models; D008297:Male; D008404:Massachusetts; D011897:Random Allocation; D012306:Risk; D012307:Risk Factors; D012737:Sex Factors