title: Facebook network structure and awareness of preexposure prophylaxis among young men who have sex with men.
abstract: Young Black men who have sex with men (YBMSM) are the only population in the United States who have experienced rising human immunodeficiency virus incidence over the past decade. Consistent pre-exposure prophylaxis (PrEP) use can substantially reduce the risk of human immunodeficiency virus acquisition. What differentiates those who become aware of PrEP, and those who do not, remains largely unknown.
  
  
  
  The social networks of YBMSM can impact their awareness of PrEP; to examine this impact, we used two waves of Facebook data from "uConnect"-a longitudinal cohort study of YBMSM in Chicago (n = 266).
  
  
  
  While PrEP awareness increased from 45% at baseline to 75% at follow-up, its use remained low (4% and 6%). There were 88 PrEP-unaware individuals at baseline who became aware (BA) by follow-up, and 56 who remained persistently unaware. While the persistently unawares had a higher median number of total Facebook friends, the BAs had a higher median numbers of friends who participated in uConnect, who were PrEP-aware, and who practiced behaviors previously found to be associated with individual-level awareness of PrEP at baseline. The BAs also had substantially more "influential" friends.
  
  
  
  These findings demonstrate the potential of social networks in raising PrEP awareness and use among YBMSM.
authors.affiliation: Department of Medicine, University of Chicago, Chicago, IL; Department of Medicine, Chicago Center for HIV Elimination, University of Chicago, Chicago, IL. Electronic address: khanna7@uchicago.edu.
authors.forename: Aditya S
authors.initials: AS
authors.lastname: Khanna
authors.affiliation: Department of Public Health Sciences, University of Chicago, Chicago, IL.
authors.forename: Phil
authors.initials: P
authors.lastname: Schumm
authors.affiliation: Department of Medicine, University of Chicago, Chicago, IL; Department of Medicine, Chicago Center for HIV Elimination, University of Chicago, Chicago, IL; Department of Public Health Sciences, University of Chicago, Chicago, IL.
authors.forename: John A
authors.initials: JA
authors.lastname: Schneider
mesh_terms: D000328:Adult; D001741:Black or African American / Q000523:psychology*; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D002641:Chicago; D015331:Cohort Studies; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control*; D006293:Health Promotion / Q000379:methods*; D018451:Homosexuality, Male / Q000523:psychology*; D006801:Humans; D015994:Incidence; D020407:Internet; D008137:Longitudinal Studies; D008297:Male; D065129:Pre-Exposure Prophylaxis / Q000379:methods; D000072339:Sexual and Gender Minorities / Q000523:psychology*; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents
keywords: Facebook and health promotion; HIV prevention; Men who have sex with men (MSM); Pre-exposure prophylaxis (PrEP); Social network modeling