title: The association between change in social network characteristics and non-fatal overdose: results from the SHIELD study in Baltimore, MD, USA.
abstract: BACKGROUND
  Social network factors have been reported to be associated with non-fatal overdose. Yet, few studies have examined how changes in social network characteristics may influence overdose risk. The purpose of this study was to examine the relationship between changes in social network and non-fatal overdose.
  
  
  METHODS
  Data for this study came from 659 participants enrolled in the Self-Help in Eliminating Life-Threatening Diseases (SHIELD) study, who reported details about their non-fatal overdose experience between enrollment and a follow-up visit. Social network characteristics were described at both time points and net change in network composition was calculated.
  
  
  RESULTS
  The sample was predominately male (56%), African-American (96%) and unemployed (78%). Experience of non-fatal overdose between time points was reported by 15%. Older age was associated with non-fatal overdose. Interaction between incarceration status and drug use was statistically significant. Protective factors were having a denser network at baseline and a network that became denser after adjusting for gender, homelessness, incarceration, drug use and total network size.
  
  
  CONCLUSIONS
  Drug users' social networks are an important target for overdose prevention interventions. Further research on overdose risk and movement of specific network members in and out of networks is warranted.
authors.affiliation: Johns Hopkins Bloomberg School of Public Health, 1629 East Baltimore Street, Baltimore, MD 21231, USA. ktobin@jhsph.edu
authors.forename: Karin E
authors.initials: KE
authors.lastname: Tobin
authors.forename: Wei
authors.initials: W
authors.lastname: Hua
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Costenbader
authors.forename: Carl A
authors.initials: CA
authors.lastname: Latkin
mesh_terms: D000328:Adult; D015142:Baltimore / Q000453:epidemiology; D003710:Demography; D062787:Drug Overdose / Q000453:epidemiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D015995:Prevalence; D011329:Prisoners / Q000706:statistics & numerical data; D012944:Social Support; D015819:Substance Abuse, Intravenous / Q000453:epidemiology* / Q000517:prevention & control*; D011795:Surveys and Questionnaires