title: Including Online-Recruited Seeds: A Respondent-Driven Sample of Men Who Have Sex With Men.
abstract: BACKGROUND
  Technology has changed the way men who have sex with men (MSM) seek sex and socialize, which may impact the implementation of respondent-driven sampling (RDS) among this population. Initial participants (also known as seeds) are a critical consideration in RDS because they begin the recruitment chains. However, little information is available on how the online-recruited seeds may effect RDS implementation.
  
  
  OBJECTIVE
  The objectives of this study were to compare (1) online-recruited versus offline-recruited seeds and (2) subsequent recruitment chains of online-recruited versus offline-recruited seeds.
  
  
  METHODS
  Between 2012 and 2014, we recruited MSM using RDS in Vancouver, Canada. RDS weights were used with logistic regression to address each objective.
  
  
  RESULTS
  A total of 119 seeds were used, 85 of whom were online-recruited seeds, to recruit an additional 600 MSM. Compared with offline-recruited seeds, online-recruited seeds were less likely to be HIV-positive (OR 0.34, 95% CI 0.13-0.88), to have attended a gay community group (AOR 0.33, 95% CI 0.12-0.90), and to feel gay community involvement was "very important" (AOR 0.16, 95% CI 0.03-0.93). Online-recruited seeds were more likely to ask a sexual partner's HIV status always versus <50% of the time (AOR 5.21, 95% CI 1.17-23.23), to have watched the Pride parade (AOR 6.30, 95% CI 1.69-23.45), and to have sought sex online (AOR 4.29, 95% CI 1.53-12-12.05). Further, compared with recruitment chains started by offline-recruited seeds, recruits from chains started by online-recruited seeds (283/600, 47.2%) were less likely to be HIV-positive (AOR 0.25, 95% CI 0.16-0.40), to report "versatile" versus "bottom" sexual position preference (AOR 0.56, 95% CI 0.35-0.88), and to be in a relationship lasting >1 year (AOR 1.65, 95% CI 1.06-2.56). Recruits of online seeds were more likely to be out as gay for longer (eg, 11-21 vs 1-4 years, AOR 2.22, 95% CI 1.27-3.88) and have fewer Facebook friends (eg, 201-500 vs >500, AOR 1.69, 95% CI 1.02-2.80).
  
  
  CONCLUSIONS
  Online-recruited seeds were more prevalent, recruited fewer participants, but were different from those recruited offline. This may therefore help create a more diverse overall sample. Our work has shown the value of geosocial networking apps for aiding RDS recruitment efforts, especially when faced with slow participation uptake by other means. Understanding the degree to which networks interact will be an important next step in confirming the efficacy of online RDS recruitment strategies.
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
authors.forename: Nathan John
authors.identifier: http://orcid.org/0000-0002-6336-8780
authors.initials: NJ
authors.lastname: Lachowsky
authors.forename: Allan
authors.identifier: http://orcid.org/0000-0001-7044-2494
authors.initials: A
authors.lastname: Lal
authors.forename: Jamie I
authors.identifier: http://orcid.org/0000-0002-8900-7350
authors.initials: JI
authors.lastname: Forrest
authors.forename: Kiffer George
authors.identifier: http://orcid.org/0000-0001-6545-1249
authors.initials: KG
authors.lastname: Card
authors.forename: Zishan
authors.identifier: http://orcid.org/0000-0002-9236-3890
authors.initials: Z
authors.lastname: Cui
authors.forename: Paul
authors.identifier: http://orcid.org/0000-0002-6411-8089
authors.initials: P
authors.lastname: Sereda
authors.forename: Ashleigh
authors.identifier: http://orcid.org/0000-0003-3742-7086
authors.initials: A
authors.lastname: Rich
authors.forename: Henry Fisher
authors.identifier: http://orcid.org/0000-0001-8621-2749
authors.initials: HF
authors.lastname: Raymond
authors.forename: Eric A
authors.identifier: http://orcid.org/0000-0002-9128-0997
authors.initials: EA
authors.lastname: Roth
authors.forename: David M
authors.identifier: http://orcid.org/0000-0003-1078-9247
authors.initials: DM
authors.lastname: Moore
authors.forename: Robert S
authors.identifier: http://orcid.org/0000-0003-3463-5488
authors.initials: RS
authors.lastname: Hogg
mesh_terms: D000293:Adolescent; D000328:Adult; D001955:British Columbia; D006679:HIV Seropositivity; D018451:Homosexuality, Male; D006801:Humans; D020407:Internet; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D015995:Prevalence; D012494:Sampling Studies; D012725:Sexual Behavior; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: HIV/AIDS; Internet; men who have sex with men; online recruitment; respondent driven sampling