title: Childhood behavior problems and age at first sexual intercourse: a prospective birth cohort study.
abstract: OBJECTIVE
  Early first sexual intercourse (FSI) is a risk factor for unplanned teenage pregnancy, sexually transmitted infection, and adverse social, emotional, and physical health outcomes in adolescence and into adulthood. The aim of this study was to examine relationships between internalizing (eg, anxious/depressed, withdrawn) and externalizing (eg, delinquent, aggressive) behavior problems in childhood and age at FSI.
  
  
  METHODS
  We used a large, population-based birth cohort (The Western Australian Pregnancy Cohort [Raine] Study) to address this question. Child behavior was measured by using the Child Behavior Checklist collected from parents at ages 2, 5, 8, 10, and 14 and scores calculated for total, internalizing, and externalizing behavior problems. At age 17, 1200 participants reported sexual behavior.
  
  
  RESULTS
  Participants with clinically significant Child Behavior Checklist scores (T ≥ 60) were at increased risk for earlier first sexual intercourse (FSI) (<16 years). Adjusted odds ratios revealed that total and externalizing behavior problems from age 5 years onward significantly increased the risk of earlier FSI for boys. In girls, externalizing problems from age 10 years increased the risk for earlier FSI. Internalizing problems at ages 8 and 10 were significantly associated with early FSI for boys but not girls.
  
  
  CONCLUSIONS
  Externalizing behavior from as early as 5 in boys and 10 in girls is a significant risk factor for earlier age at FSI. Adolescent sexual health promotion should consider early intervention in children with behavior problems, particularly boys.
authors.affiliation: Discipline of Paediatrics and Child Health, rachel.skinner@health.nsw.gov.au.
authors.forename: S Rachel
authors.initials: SR
authors.lastname: Skinner
authors.affiliation: Telethon Institute for Child Health Research.
authors.forename: Monique
authors.initials: M
authors.lastname: Robinson
authors.affiliation: Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom;
authors.forename: Michael A
authors.initials: MA
authors.lastname: Smith
authors.affiliation: Sexually Transmitted Infections Research Centre, The University of Sydney, Sydney, Australia;
authors.forename: Spring Chenoa Cooper
authors.initials: SC
authors.lastname: Robbins
authors.affiliation: Telethon Institute for Child Health Research.
authors.forename: Eugen
authors.initials: E
authors.lastname: Mattes
authors.affiliation: Biostatistics and Research Design Unit, Women and Infants Research Foundation, Perth, Australia;
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Cannon
authors.affiliation: Columbia University College of Physicians and Surgeons and Morgan Stanley Children's Hospital, New York, New York; and.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Rosenthal
authors.affiliation: Columbia University College of Physicians and Surgeons and Morgan Stanley Children's Hospital, New York, New York; and.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Marino
authors.affiliation: Department of Obstetrics and Gynaecology, University of Melbourne, and the Royal Women's Hospital Melbourne, Melbourne, Australia.
authors.forename: Martha
authors.initials: M
authors.lastname: Hickey
authors.affiliation: Sexually Transmitted Infections Research Centre, The University of Sydney, Sydney, Australia; School of Women's and Infants' Health, The University of Western Australia, Perth, Australia;
authors.forename: Dorota A
authors.initials: DA
authors.lastname: Doherty
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002653:Child Behavior Disorders / Q000453:epidemiology* / Q000523:psychology*; D002675:Child, Preschool; D015331:Cohort Studies; D003075:Coitus / Q000523:psychology*; D005260:Female; D006801:Humans; D007389:Internal-External Control; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014904:Western Australia
keywords: Raine Study; adolescence; risky behavior; sexual debut