title: Targeted Facebook Advertising is a Novel and Effective Method of Recruiting Participants into a Human Papillomavirus Vaccine Effectiveness Study.
abstract: BACKGROUND
  Targeted advertising using social networking sites (SNS) as a recruitment strategy in health research is in its infancy.
  
  
  OBJECTIVE
  The aim of this study was to determine the feasibility of targeted Facebook advertisements to increase recruitment of unvaccinated women into a human papillomavirus (HPV) vaccine effectiveness study.
  
  
  METHODS
  Between September 2011 and November 2013, females aged 18 to 25 years, residing in Victoria, Australia, were recruited through Facebook advertisements relating to general women's health. From November 2013 to June 2015, targeted advertising campaigns were implemented to specifically recruit women who had not received the HPV vaccine. Consenting participants were invited to complete an online questionnaire and those who had ever had sexual intercourse were asked to provide a self-collected vaginal swab. The HPV vaccination status of participants was confirmed from the National HPV Vaccination Program Register (NHVPR).
  
  
  RESULTS
  The campaign comprised 10 advertisements shown between September 2011 and June 2015 which generated 55,381,637 impressions, yielding 23,714 clicks, at an overall cost of AUD $22,078.85. A total of 919 participants were recruited. A greater proportion of unvaccinated women (50.4%, 131/260) were recruited into the study following targeted advertising, compared with those recruited (19.3%, 127/659) prior to showing the modified advertisement (P<.001). A greater proportion of the total sample completed tertiary education and resided in inner regional Victoria, compared with National population census data (P<.001), but was otherwise representative of the general population.
  
  
  CONCLUSIONS
  Targeted Facebook advertising is a rapid and cost-effective way of recruiting young unvaccinated women into a HPV vaccine effectiveness study.
authors.affiliation: Royal Women's Hospital, Department of Microbiology and Infectious Diseases, Parkville, Australia. asvini.subasinghe@mcri.edu.au.
authors.forename: Asvini K
authors.identifier: http://orcid.org/0000-0001-6045-2728
authors.initials: AK
authors.lastname: Subasinghe
authors.forename: Margaret
authors.identifier: http://orcid.org/0000-0002-0347-3933
authors.initials: M
authors.lastname: Nguyen
authors.forename: John D
authors.identifier: http://orcid.org/0000-0003-2431-7902
authors.initials: JD
authors.lastname: Wark
authors.forename: Sepehr N
authors.identifier: http://orcid.org/0000-0002-5556-4175
authors.initials: SN
authors.lastname: Tabrizi
authors.forename: Suzanne M
authors.identifier: http://orcid.org/0000-0002-6869-311X
authors.initials: SM
authors.lastname: Garland
keywords: Facebook; HPV; human papillomavirus; online recruitment; social media