title: Changes in the Distribution of Sex Partners in the United States: 2002 to 2011-2013.
abstract: The purpose of the current analysis is to examine subgroup differences in the distribution of opposite-sex sex partners in the United States across an approximate 10-year period to identify patterns that may inform sexually transmitted infection research and prevention.
  
  
  
  Data were drawn from the 2002 and 2011-2013 National Survey of Family Growth, a US probability-based household survey focusing on sexual and reproductive health. The measures included in this analysis were lifetime opposite-sex sex partners and opposite-sex sex partners in the past year. Analyses were conducted separately for men and women. All analyses were conducted in R and R-studio with the "survey" package, focusing on medians, the 80th, and 95th quartile.
  
  
  
  In 2002, there were significant differences between men and women in median number of lifetime sex partners with men reporting more lifetime partners. However, in the 2011-2013 data, these differences are no longer significant. Still, the findings suggest that the top 20% and top 5% of men are reporting significantly more lifetime partners than their female counterparts. In comparison, partners in the past year remain relatively unchanged for both men and women.
  
  
  
  These findings suggest that there were important changes in the distribution of sex partners between 2002 and 2011-2013 that have implications for sexually transmitted infection prevention. Median lifetime partners are no longer different for women and men: however, the distribution of lifetime partners among men is becoming even more skewed.
authors.affiliation: From the Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Harper
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Dittus
authors.forename: Jami S
authors.initials: JS
authors.lastname: Leichliter
authors.forename: Sevgi O
authors.initials: SO
authors.lastname: Aral
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D012306:Risk; D012725:Sexual Behavior; D012747:Sexual Partners; D012749:Sexually Transmitted Diseases / Q000517:prevention & control*; D055815:Young Adult