title: The effects of social networks on tobacco use among high-school adolescents in Mexico.
abstract: OBJECTIVE
  To identify the effect of centrality in social network positions on tobacco-use among high-school adolescents in Tonala, Jalisco, Mexico.
  
  
  METHODS
  Longitudinal sociometric social network data were collected among 486 high-school adolescents in 2003 and 399 in 2004. The survey included: social network components, smoking and sociodemographic characteristics. Social network measures of centrality were calculated and multivariate logistic regression was used.
  
  
  RESULTS
  Ever used tobacco (OR= 44.98), marginalized-low stratum (OR= 2.16) and in-degree (OR=1.10) predicted tobacco use. Out-degree (OR= 0 .89) and out-in-degree (OR= 0.90) protected against tobacco use.
  
  
  CONCLUSIONS
  Nominating more friends rather than receiving such nominations was protective for tobacco use. Popular students, those receiving many nominations, were at higher risk for tobacco use. Involvement of leaders with capacity to influence might be an efficient strategy for dissemination of preventive messages.
authors: Centro de Seguridad Social Manzanillo, Instituto Mexicano del Seguro Social, Colima, Mexico. ishaoro@hotmail.com
authors: Guadalupe
authors: G
authors: Ramírez-Ortiz
authors: Ramiro
authors: R
authors: Caballero-Hoyos
authors: Guadalupe
authors: G
authors: Ramírez-López
authors: Thomas W
authors: TW
authors: Valente
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D005260:Female; D005500:Follow-Up Studies; D033062:Friends; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D010379:Peer Group; D000297:Psychology, Adolescent; D012574:Schools; D012907:Smoking / Q000453:epidemiology / Q000523:psychology*; D012934:Social Isolation; D012944:Social Support; D013334:Students / Q000523:psychology; D011795:Surveys and Questionnaires