title: Concordance in perceived partner types and unprotected sex among couples of adolescents and young adults: analysis of reciprocally nominated heterosexual dyads.
abstract: OBJECTIVE
  The objectives of this study were to examine the reciprocity of adolescents' heterosexual relationships, the concordance in perceived partner types reported by partners among reciprocal dyads, and the association between dyad-level unprotected sex and relationship types.
  
  
  METHODS
  Data were obtained from the Bayview Network Study (San Francisco, California, USA), designed to examine the prevalence of STI risk behaviours and transmission patterns among adolescents between July 2000 and October 2001. For reciprocal dyads, Kappa statistics was used to determine the level of agreement between partner types reported by two sex partners. Multivariate logistic regressions were used to determine the odds of couple's unprotected sex.
  
  
  RESULTS
  A total of 782 unique heterosexual relationships were identified. Less than one-third were reciprocally nominated heterosexual dyads. A total of first observed 211 reciprocal dyads were reported by 198 females and 179 males. Agreement on partner type between adolescents and their sex partners among reciprocal dyads was poor, although main-main concordant relationships were the most frequent group (66.4%). Male partner's age and length of relationship significantly increased the odds of a couple's unprotected sex (adjusted OR=1.4, and 1.2, p<0.05), and male partner's frequency of sex significantly decreased the odds (adjusted OR=0.69, p<0.05). The concordance of partner type by two sex partners was not significantly related to couples' unprotected sex when other covariates were taken into account.
  
  
  CONCLUSIONS
  This unique study advances knowledge about individuals' perception of their heterosexual partner types in reported relationships: the majority of adolescent couples were not reciprocally acknowledged, and whether or not two sex partners agreed on partner type did not change the odds of a couple's unprotected sex even among reciprocal dyads.
authors.affiliation: The Johns Hopkins University School of Medicine, Department of Pediatrics, Baltimore, MD 21224, USA. myamaza1@jhmi.edu
authors.forename: Michiyo
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Donna
authors.initials: D
authors.lastname: Strobino
authors.forename: Jonathan
authors.initials: J
authors.lastname: Ellen
mesh_terms: D000293:Adolescent; D017280:Condoms / Q000706:statistics & numerical data; D005260:Female; D020010:Heterosexuality / Q000523:psychology* / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D010465:Perception; D012495:San Francisco; D012747:Sexual Partners / Q000523:psychology*; D012944:Social Support; D047568:Unsafe Sex / Q000523:psychology* / Q000706:statistics & numerical data; D055815:Young Adult