title: [Barras bravas membership and its influence on drug use].
abstract: OBJECTIVE
  To identify the factors associated with barras bravas (soccer fans clubs) membership, the incidence in drug use and the association between membership and drug use.
  
  
  METHODS
  This report analyzed data from 1303 adolescent scholars who participated in two stages (T1 and T2) of a longitudinal study done in 23 schools of Bogota during 2006- 2007, selected through a probabilistic sampling stratified by clusters. Logistic regression models were implemented in order to evaluate the associations of interest.
  
  
  RESULTS
  In T1, 8,2% of the surveyed students reported barras bravas membership. After one year of follow-up, 14,2% of barras bravas members, and 4,6% of non-members, initiated drug use. The association between barras bravas membership and drug use onset remained significant after adjusting for multiple confounding factors (ARR=2,4; 95%CI=1,2-4,7). Sex-stratified analysis indicated that this association remained statistically significant only for females (ARR=6,1; 95%CI=2,5-15,3).
  
  
  CONCLUSIONS
  Barras bravas membership increases the risk of drug use onset, particularly among females. The findings imply that preventive efforts should be focused on females in these contexts.
authors.affiliation: Braun School of Public Health & Community Medicine, Hebrew University-Hadassah, Jerusalem, Israel. catalina.lopez@mail.huji.ac.il
authors.forename: Catalina
authors.initials: C
authors.lastname: López-Quintero
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Neumark
mesh_terms: D000293:Adolescent; D003105:Colombia; D005260:Female; D006126:Group Processes; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D012916:Soccer; D019966:Substance-Related Disorders / Q000453:epidemiology*