title: Social network analysis identified central outcomes for core outcome sets using systematic reviews of HIV/AIDS.
abstract: OBJECTIVE
  Methods to develop core outcome sets, the minimum outcomes that should be measured in research in a topic area, vary. We applied social network analysis methods to understand outcome co-occurrence patterns in human immunodeficiency virus (HIV)/AIDS systematic reviews and identify outcomes central to the network of outcomes in HIV/AIDS.
  
  
  METHODS
  We examined all Cochrane reviews of HIV/AIDS as of June 2013. We defined a tie as two outcomes (nodes) co-occurring in ≥2 reviews. To identify central outcomes, we used normalized node betweenness centrality (nNBC) (the extent to which connections between other outcomes in a network rely on that outcome as an intermediary). We conducted a subgroup analysis by HIV/AIDS intervention type (i.e., clinical management, biomedical prevention, behavioral prevention, and health services).
  
  
  RESULTS
  The 140 included reviews examined 1,140 outcomes, 294 of which were unique. The most central outcome overall was all-cause mortality (nNBC = 23.9). The most central and most frequent outcomes differed overall and within subgroups. For example, "adverse events (specified)" was among the most central but not among the most frequent outcomes, overall.
  
  
  CONCLUSIONS
  Social network analysis methods are a novel application to identify central outcomes, which provides additional information potentially useful for developing core outcome sets.
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Room W6507-B, Baltimore, MD 21205, USA. Electronic address: isaldan1@jhmi.edu.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Saldanha
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Room E6011, Baltimore, MD 21205, USA.
authors.forename: Tianjing
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Health, Behavior, and Society, Johns Hopkins Bloomberg School of Public Health, 2213 McElderry Street, 2nd Floor, Baltimore, MD 21205, USA.
authors.forename: Cui
authors.initials: C
authors.lastname: Yang
authors.affiliation: Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA; Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, SMP, Lima 31, Peru.
authors.forename: Cesar
authors.initials: C
authors.lastname: Ugarte-Gil
authors.affiliation: Department of Epidemiology and Biostatistics, University of California, San Francisco, 550 16th Street, Box 1224, San Francisco, CA 94143, USA.
authors.forename: George W
authors.initials: GW
authors.lastname: Rutherford
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Room E6152, Baltimore, MD 21205, USA.
authors.forename: Kay
authors.initials: K
authors.lastname: Dickersin
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology* / Q000401:mortality; D015658:HIV Infections / Q000453:epidemiology* / Q000401:mortality; D006801:Humans; D017063:Outcome Assessment, Health Care; D012196:Review Literature as Topic; D012944:Social Support
keywords: Core outcome sets; HIV/AIDS; Outcomes; Randomized controlled trials; Social network analysis; Systematic reviews