title: [Sexual intercourse debut and associated factors in Mexican students aged 14-19 years in public schools].
abstract: OBJECTIVE
  To estimate the mean age of sexual intercourse debut (SID) and associated family and individual factors in 14-19-year-olds of both sexes in the 32 states of Mexico in 2007.
  
  
  METHODS
  A cross-sectional study was conducted of a representative sample of 9,893 students aged between 14 and 19 years old. The data were collected through a self-administered, anonymous and voluntary questionnaire. Logistic regression models were used to estimate odds ratios (OR) with 95% confidence intervals (95%CI) by category: no SID, SID at 10-15 years and SID at 16-19 years.
  
  
  RESULTS
  The national mean age of SID was 16 years, being 15 years for boys (95%CI: 15.88-16.11) and 16 years for girls (95%CI: 15.26-15.42). Factors associated with SID in boys were disadvantaged socioeconomic level (OR=0.66; 95%CI: 0.46-0.94), living with parents (OR=0.65; 95%CI: 0.56-0.75), less offensive communication between parents and boys/girls (OR=0.66; 95%CI: 0.57-0.77), and high social self-esteem (OR=1.68; 95%CI: 1.35-1.77). Factors associated with SID in girls were traditional gender beliefs (OR=0.49; 95%CI: 0.32-0.74), high depressive symptoms (OR=1.88; 95%CI: 1.19-2.99), and high family self-esteem (OR= 0.50; 95%CI: 0.38-0.65).
  
  
  CONCLUSIONS
  In Mexico, SID occurred early in boys. In addition, the findings of this study show that in Mexico, the age of SID and associated factors differ in boys and girls. The age of SID is strongly influenced by gender and cultural beliefs.
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: Leonor
authors.initials: L
authors.lastname: Rivera-Rivera
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México. Electronic address: leyvalop@insp.mx.
authors.forename: Ahidée
authors.initials: A
authors.lastname: Leyva-López
authors.affiliation: Centro de Investigación en Nutrición y Salud, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: Armando
authors.initials: A
authors.lastname: García-Guerra
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: Filipa
authors.initials: F
authors.lastname: de Castro
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: Dolores
authors.initials: D
authors.lastname: González-Hernández
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: Lilia Margarita
authors.initials: LM
authors.lastname: de Los Santos
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D000367:Age Factors; D003075:Coitus; D003430:Cross-Sectional Studies; D003469:Culture; D003863:Depression / Q000453:epidemiology; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D012649:Self Concept; D012737:Sex Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Adolescentes; Adolescents; Autoestima; Conducta sexual; México; Self esteem; Sexual behavior