title: Prospective association between negative life events and initiation of sexual intercourse: the influence of family structure and family income.
abstract: OBJECTIVE
  We examined the prospective association between negative life events and time to initiation of sexual intercourse and the influence of family structure and family income on this association.
  
  
  METHODS
  We followed up a randomly selected sample (n=649) of ethnically diverse parents and their children aged 12 to 17 years over a 5-year period. We conducted Cox proportional hazards regression analysis to examine the relation between negative life events and time to initiation of sexual intercourse. Family structure and family income were assessed as confounders.
  
  
  RESULTS
  Negative life events were significant predictors of time to initiation of sexual intercourse in adolescents. After controlling for demographic variables, youths reporting 1 negative life event had a hazard of initiation of sexual intercourse 1.40 times greater and youths reporting 2 or more negative life events had a hazard of initiation of sexual intercourse 1.61 times greater compared with youths reporting no negative life events. Family structure and family income were not significant confounders of the relation between initiation of sexual intercourse and negative life events.
  
  
  CONCLUSIONS
  Interventions to prevent initiation of sexual intercourse should focus on youths with recent negative life events, regardless of family income and structure.
authors.affiliation: Marshall K. Cheney is with the Department of Health and Exercise Science, University of Oklahoma, Norman. Roy F. Oman, Eleni L. Tolma, and Robert John are with the Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City. Sara K. Vesely is with the Department of Biostatistics and Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City. Cheryl B. Aspy is with the Department of Family and Preventive Medicine, University of Oklahoma Health Sciences Center, Oklahoma City.
authors.forename: Marshall K
authors.initials: MK
authors.lastname: Cheney
authors.forename: Roy F
authors.initials: RF
authors.lastname: Oman
authors.forename: Sara K
authors.initials: SK
authors.lastname: Vesely
authors.forename: Cheryl B
authors.initials: CB
authors.lastname: Aspy
authors.forename: Eleni L
authors.initials: EL
authors.lastname: Tolma
authors.forename: Robert
authors.initials: R
authors.lastname: John
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D003075:Coitus; D005191:Family Characteristics; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008016:Life Change Events; D008137:Longitudinal Studies; D008297:Male; D009825:Oklahoma; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012044:Regression Analysis; D012959:Socioeconomic Factors; D055815:Young Adult