title: Sexual timetables for oral-genital, vaginal, and anal intercourse: sociodemographic comparisons in a nationally representative sample of adolescents.
abstract: OBJECTIVE
  We documented the prevalence and relative timing of oral-genital, vaginal, and anal intercourse during adolescence and examined whether these timetables varied by sociodemographic factors.
  
  
  METHODS
  We used data from almost 14 ,000 Wave IV respondents to the National Longitudinal Study of Adolescent Health to generate prevalence estimates for adolescents who reached age 18 years by 2001 and logistic and ordinary least squares regression to examine sociodemographic correlates of sexual patterns.
  
  
  RESULTS
  One in 5 adolescents did not engage in any of these sexual behaviors by age 18 years. More than two thirds reported vaginal or oral-genital sexual activity, but only about half experienced both. One in 10 reported anal intercourse experience. A third initiated 2 or more behaviors within a 1-year period. In longer timetables, vaginal intercourse was more often initiated first. Most sociodemographic characteristics examined were uniquely associated with prevalence and sexual timing.
  
  
  CONCLUSIONS
  Diversity in patterns of sexual initiation occurring in the 1990s underscores the ongoing need for comprehensive and nuanced examinations of adolescent sexual trajectories and their implications for sexual health in more recent cohorts.
authors.affiliation: Department of Maternal and Child Health, Gillings School of Global Public Health and Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-8120, USA. carolyn_halpern@unc.edu
authors.forename: Carolyn Tucker
authors.initials: CT
authors.lastname: Halpern
authors.forename: Abigail A
authors.initials: AA
authors.lastname: Haydon
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D015331:Cohort Studies; D003075:Coitus; D004522:Educational Status; D005006:Ethnicity; D005191:Family Characteristics; D006801:Humans; D008137:Longitudinal Studies; D015995:Prevalence; D011446:Prospective Studies; D012737:Sex Factors; D012725:Sexual Behavior / Q000208:ethnology / Q000706:statistics & numerical data*; D013997:Time Factors; D014481:United States / Q000453:epidemiology