title: [Sexual behavior and gender differences among adolescents consulting at a university public health system].
abstract: BACKGROUND
  The predetermined gender roles and the emphasis on reproductive responsibility on women, excluding men, have negative consequences on their sexual reproductive health and satisfactory sexual practices.
  
  
  OBJECTIVE
  To describe and analyze changes in sexual practices and gender differences in adolescents of the lower-middle socioeconomic level, users of public health system who started their sexual activity.
  
  
  METHODS
  We studied 4,971 adolescents of both sexes aged between 12 and 19 years, who consulted in a clinic for adolescents between the years 1990 and 2005. Several variables related to adolescent sexuality were considered. Uni and bivariate analysis were carried out and a model of stratified lineal regression per sex was fixed to explain the following variables: age at which sexual activity is initiated, number of sexual partners, time period between start of dating and the start of sexual activity along time.
  
  
  RESULTS
  The average age when men and women start their sexual activity was 15.7 and 15.5 years, respectively. Along years and among women but not men, there was a reduction in the age of start of sexual activity and an increase in the number of sexual partners. The mean lapse between start of dating and the start of sexual activity in men and women was 6.2 and 7.5 months, respectively. This figure had an 11.696 and 13.9% reduction per year of study in females and males, respectively.
  
  
  CONCLUSIONS
  There is an increasing expansion of sexual roles in adolescents, but certain patterns of contradictory conservative reasoning are maintained.
authors.affiliation: Centro de Medicina Reproductiva y Desarrollo Integral de la Adolescencia, Facultad de Medicina, Universidad de ChileSantiago, Chile. cemera@med.uchile.cl
authors.forename: Electra
authors.initials: E
authors.lastname: González A
authors.forename: Temístocles
authors.initials: T
authors.lastname: Molina G
authors.forename: Adela
authors.initials: A
authors.lastname: Montero
authors.forename: Vania
authors.initials: V
authors.lastname: Martínez N
authors.forename: Carolina
authors.initials: C
authors.lastname: Leyton M
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D016497:Adolescent Health Services / Q000706:statistics & numerical data*; D000328:Adult; D002648:Child; D003268:Contraception Behavior / Q000523:psychology / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D017150:Public Sector; D012737:Sex Factors; D012725:Sexual Behavior / Q000523:psychology / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors