title: Effectiveness of social media in reducing risk factors for noncommunicable diseases: a systematic review and meta-analysis of randomized controlled trials.
abstract: OBJECTIVE
  The primary aim of the current study was to synthesize evidence of the effect of social media use compared with no social media use as part of interventions to reduce risk factors for noncommunicable diseases.
  
  
  METHODS
  Databases were searched up to June 10, 2014, using medical subject headings. A secondary aim of this study was to assess the effectiveness of social media use compared with no social media use in reducing the risk factors for noncommunicable diseases, stratifying the results by the extent of bias on outcomes, by social media use alone, and by the levels of social presence and media richness.
  
  
  METHODS
  Sixteen trials (n=10,711 participants) met the inclusion criteria, but interventions mostly used social media with low levels of media richness and presence (e.g., discussion boards, bulletin boards).
  
  
  RESULTS
  Meta-analysis of all trials showed no significant differences (standardized mean difference [SMD] -0.14; 95%CI -0.28 to 0.01), with similar findings for physical activity (SMD 0.07; 95%CI -0.25 to 0.38), body weight (SMD 0.07; 95%CI -0.17 to 0.20), and fruit and vegetable intake (SMD 0.39; 95%CI -0.11 to 0.89). Trials assessing social media interventions aimed at modifying risk factors for noncommunicable diseases showed that social media use improved the primary outcomes, but the overall quality of the included studies limits the generalizability of these findings.
  
  
  CONCLUSIONS
  Further trials are warranted, especially to isolate the effect of social media use and to fully evaluate the effect of the social presence and media richness of social media platforms.
authors.affiliation: G. Mita is with the School of Population Health, University of Auckland, New Zealand. C. Ni Mhurchu is with the National Institute for Health Innovation, University of Auckland, New Zealand. A Jull is with the School of Nursing and National Institute for Health Innovation, University of Auckland, New Zealand. gmit015@aucklanduni.ac.nz.
authors.forename: George
authors.initials: G
authors.lastname: Mita
authors.affiliation: G. Mita is with the School of Population Health, University of Auckland, New Zealand. C. Ni Mhurchu is with the National Institute for Health Innovation, University of Auckland, New Zealand. A Jull is with the School of Nursing and National Institute for Health Innovation, University of Auckland, New Zealand.
authors.forename: Cliona
authors.initials: C
authors.lastname: Ni Mhurchu
authors.affiliation: G. Mita is with the School of Population Health, University of Auckland, New Zealand. C. Ni Mhurchu is with the National Institute for Health Innovation, University of Auckland, New Zealand. A Jull is with the School of Nursing and National Institute for Health Innovation, University of Auckland, New Zealand.
authors.forename: Andrew
authors.initials: A
authors.lastname: Jull
mesh_terms: D003142:Communication; D005260:Female; D006801:Humans; D008297:Male; D011634:Public Health; D012307:Risk Factors; D061108:Social Media
keywords: fruit and vegetable intake; physical activity; social media; weight change