title: Population-level evaluation of school-based interventions to prevent problem substance use among gay, lesbian and bisexual adolescents in Canada.
abstract: OBJECTIVE
  This study examined whether students' odds of recent substance use were lower in the presence of gay-straight alliances or explicit anti-homophobia policy that had been established at their school recently, or at least 3 years prior.
  
  
  METHODS
  We analyzed a population-based sample of students in grades 8 through 12 from the British Columbia Adolescent Health Survey of 2008 (weighted N=21,708). We used multi-nomial logistic regressions to test the hypothesized effects of gay-straight alliances and policies on substance use outcomes for lesbian, gay and bisexual students, and heterosexual students separately.
  
  
  RESULTS
  Results indicated that gay-straight alliances and anti-homophobic bullying policies were linked to significantly lower odds of some but not all types of recent risky alcohol use, and past-year harms from alcohol or drug use, but almost exclusively in schools where the policies or gay-straight alliances had been established for at least 3 years; and among lesbian, gay and bisexual adolescents, only for girls.
  
  
  CONCLUSIONS
  Our findings suggest that these school-based strategies (gay-straight alliances and anti-homophobia policies) to reduce homophobia and foster school inclusion may be beneficial in reducing problem alcohol use among all students, not just sexual minority students.
authors.affiliation: School of Nursing, University of British Columbia, T201-2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada. Electronic address: c.konishi@alumni.ubc.ca.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Konishi
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Saewyc
authors.forename: Yuko
authors.initials: Y
authors.lastname: Homma
authors.forename: Colleen
authors.initials: C
authors.lastname: Poon
mesh_terms: D000293:Adolescent; D000437:Alcoholism / Q000453:epidemiology / Q000517:prevention & control; D001727:Bisexuality / Q000523:psychology / Q000706:statistics & numerical data*; D001955:British Columbia / Q000453:epidemiology; D005260:Female; D018452:Homosexuality, Female / Q000523:psychology / Q000706:statistics & numerical data*; D018451:Homosexuality, Male / Q000523:psychology / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology / Q000517:prevention & control; D015397:Program Evaluation; D012572:School Health Services; D019966:Substance-Related Disorders / Q000453:epidemiology / Q000517:prevention & control*
keywords: Gay–straight alliances; School-based interventions; Sexual minority youth; Substance use