title: Preparing for the Rollout of Pre-Exposure Prophylaxis (PrEP): A Vignette Survey to Identify Intended Sexual Behaviors among Women in Kenya and South Africa if Using PrEP.
abstract: BACKGROUND
  Several clinical trials have demonstrated the efficacy of pre-exposure prophylaxis (PrEP) in reducing HIV risk. One concern with introducing PrEP is whether users will engage in riskier sexual behaviors.
  
  
  METHODS
  We assessed the effect that PrEP may have on sexual risk behaviors by administering a survey to 799 women in Bondo, Kenya, and Pretoria, South Africa. Participants were asked about their sexual behavior intentions twice--once as if they were taking PrEP and once as if they were not taking PrEP--within four risk situations (vignettes). They responded using a 5-point ordinal scale. We used a series of linear mixed effects models with an unstructured residual covariance matrix to estimate the between- and within-subject differences in the mean likelihood of engaging in risky sexual behavior across the PrEP and non-PrEP contexts. We also calculated the total percentage of participants who reported a greater likelihood of engaging in risky sexual behavior if taking PrEP than if not taking PrEP, by vignette.
  
  
  RESULTS
  We found statistically significant differences in the mean likelihood of engaging in risky sexual behavior with the between-subject comparison (-0.17, p < 0.01) and with the within-subject comparison (-0.31, p < 0.001). Depending on the vignette, 27% to 40% of participants reported a greater likelihood of engaging in risky sexual behavior if taking PrEP than if not taking PrEP.
  
  
  CONCLUSIONS
  Our findings indicate that modest increases in risky sexual behavior could occur with PrEP. Although responses from the majority of participants suggest they would not be more likely to engage in risky sexual behavior if they took PrEP, a substantial proportion might. Programs rolling out PrEP should be prepared to assist similar women in making informed choices about reducing their risk of HIV and about their sexual health beyond HIV prevention.
authors.affiliation: Social and Behavioral Health Sciences, FHI 360, Durham, NC, United States of America.
authors.forename: Amy
authors.initials: A
authors.lastname: Corneli
authors.affiliation: Biostatistics, FHI 360, Durham, NC, United States of America.
authors.forename: Samuel
authors.initials: S
authors.lastname: Field
authors.affiliation: Social and Behavioral Health Sciences, FHI 360, Durham, NC, United States of America.
authors.forename: Emily
authors.initials: E
authors.lastname: Namey
authors.affiliation: Impact Research and Development Organization, Kisumu, Kenya.
authors.forename: Kawango
authors.initials: K
authors.lastname: Agot
authors.affiliation: Setshaba Research Centre, Pretoria, South Africa.
authors.forename: Khatija
authors.initials: K
authors.lastname: Ahmed
authors.affiliation: Impact Research and Development Organization, Kisumu, Kenya.
authors.forename: Jacob
authors.initials: J
authors.lastname: Odhiambo
authors.affiliation: Setshaba Research Centre, Pretoria, South Africa.
authors.forename: Joseph
authors.initials: J
authors.lastname: Skhosana
authors.affiliation: Social and Behavioral Health Sciences, FHI 360, Durham, NC, United States of America.
authors.forename: Greg
authors.initials: G
authors.lastname: Guest
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D015658:HIV Infections / Q000517:prevention & control / Q000523:psychology*; D006801:Humans; D007630:Kenya; D065129:Pre-Exposure Prophylaxis / Q000706:statistics & numerical data*; D012309:Risk-Taking; D012725:Sexual Behavior / Q000523:psychology*; D013019:South Africa