title: Factors associated with the onset of sexual activity among Greek high school students.
abstract: OBJECTIVE
  To record variables of the sexual behaviour of high school students in Northern Greece and to investigate factors associated with the onset of sexual activity.
  
  
  METHODS
  A questionnaire (Centers of Disease Control /Prevention) adapted to national characteristics, was distributed to students from a representative sample of 11 high schools (7 public, 2 private, 2 vocational). A total of 523 students (1st, 2nd, 3rd grade) completed the questionnaire. Frequencies of certain sexual behaviours were estimated and multivariable logistic regression models were used to evaluate correlates of the onset of sexual activity.
  
  
  RESULTS
  Onset of sexual activity was reported by 48% of adolescents, half of whom stated this had occurred by the age of 15. At last sexual intercourse 76% had used a condom and 21% no contraception at all. Initiation of sexual activity was influenced by gender, age, type of school and smoking. Boys, students attending vocational high schools and smokers were significantly more likely to have been sexually active.
  
  
  CONCLUSIONS
  Sexually-related behaviours among Greek high school students are quite frequent; they should be regularly registered. Sexual education programmes specifically designed for youths must be implemented.
authors.affiliation: 4th Department of Paediatrics, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Magdalini
authors.initials: M
authors.lastname: Patseadou
authors.forename: Assimina
authors.initials: A
authors.lastname: Galli-Tsinopoulou
authors.forename: Dimitrios G
authors.initials: DG
authors.lastname: Goulis
authors.forename: Malamatenia
authors.initials: M
authors.lastname: Arvanitidou
mesh_terms: D000293:Adolescent; D040343:Behavioral Risk Factor Surveillance System; D003075:Coitus / Q000523:psychology; D017280:Condoms / Q000706:statistics & numerical data; D003268:Contraception Behavior / Q000706:statistics & numerical data; D005260:Female; D006115:Greece; D006801:Humans; D016015:Logistic Models; D008297:Male; D012574:Schools; D012725:Sexual Behavior / Q000523:psychology / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors; D013334:Students / Q000523:psychology* / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D055815:Young Adult