title: Early initiation of sexual activity: a risk factor for sexually transmitted diseases, HIV infection, and unwanted pregnancy among university students in China.
abstract: BACKGROUND
  To explore any association between the timing of the initiation of sexual activity and sexual behaviors and risks among university students in China.
  
  
  METHODS
  Data were derived from a cross-sectional study on sexual behavior among university students conducted in Ningbo municipality, China, at the end of 2003. Students completed a self-administered, structured questionnaire. Of 1981 sexually active male students, 1908 (96.3%) completed the item for timing of the initiation of sexual activity and were included in bivariate trend analyses and multiple logistic regression analyses to compare the association between this timing and sexual behavior and risks.
  
  
  RESULTS
  Male early sexual initiators had a significantly higher risk profile, including a significantly higher proportion reporting non-regular partners (i.e., casual or commercial partners), multiple partners, diagnosis with a sexually transmitted disease (STD), partner history of pregnancy, partner history of induced abortion, and less condom and oral contraceptive use, compared with late initiators. Multivariate analyses confirmed the increased likelihood of these risks in early initiators versus late initiators, other than partner type during the last year.
  
  
  CONCLUSIONS
  Our results showed that, compared to late initiators, people who initiated sexual activity early engaged in more risky behaviors that could lead to elevated risks of unwanted pregnancies and STDs or human immunodeficiency virus infection. Sex-education strategies should be focused on an earlier age, should include advice on delaying the age of first sexual activity, and should target young people who continue to take sexual risks.
authors.affiliation: Center for Disease Control and Prevention of Zhejiang Province, Hangzhou, PR China. qiaoqinma@yahoo.com.cn
authors.forename: Qiaoqin
authors.initials: Q
authors.lastname: Ma
authors.forename: Masako
authors.initials: M
authors.lastname: Ono-Kihara
authors.forename: Liming
authors.initials: L
authors.lastname: Cong
authors.forename: Guozhang
authors.initials: G
authors.lastname: Xu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Pan
authors.forename: Saman
authors.initials: S
authors.lastname: Zamani
authors.forename: Shahrzad Mortazavi
authors.initials: SM
authors.lastname: Ravari
authors.forename: Dandan
authors.initials: D
authors.lastname: Zhang
authors.forename: Takayuki
authors.initials: T
authors.lastname: Homma
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kihara
mesh_terms: D000367:Age Factors; D002681:China / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000453:epidemiology*; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D011247:Pregnancy; D011275:Pregnancy, Unwanted; D012044:Regression Analysis; D012307:Risk Factors; D012725:Sexual Behavior; D012749:Sexually Transmitted Diseases / Q000453:epidemiology*; D013334:Students; D014495:Universities; D055815:Young Adult