title: A methodological approach to the analysis of egocentric social networks in public health research: a practical example.
abstract: BACKGROUND
  Research on social networks in public health focuses on how social structures and relationships influence health and health-related behaviour. While the sociocentric approach is used to study complete social networks, the egocentric approach is gaining popularity because of its focus on individuals, groups and communities.
  
  
  METHODS
  One of the participants of the healthy lifestyle health education workshop 'I'm moving', included in the study of social support for exercise was randomly selected. The participant was denoted as the ego and members of her/his social network as the alteri. Data were collected by personal interviews using a self-made questionnaire. Numerical methods and computer programmes for the analysis of social networks were used for the demonstration of analysis.
  
  
  RESULTS
  The size, composition and structure of the egocentric social network were obtained by a numerical analysis. The analysis of composition included homophily and homogeneity. Moreover, the analysis of the structure included the degree of the egocentric network, the strength of the ego-alter ties and the average strength of ties. Visualisation of the network was performed by three freely available computer programmes, namely: Egonet.QF, E-net and Pajek. The computer programmes were described and compared by their usefulness.
  
  
  CONCLUSIONS
  Both numerical analysis and visualisation have their benefits. The decision what approach to use is depending on the purpose of the social network analysis. While the numerical analysis can be used in large-scale population-based studies, visualisation of personal networks can help health professionals at creating, performing and evaluation of preventive programmes, especially if focused on behaviour change.
authors.affiliation: University of Ljubljana, Faculty of Medicine, Public Health Centre, Zaloška 4, 1000 Ljubljana, Slovenia.
authors.forename: Janet Klara
authors.initials: JK
authors.lastname: Djomba
authors.affiliation: University of Ljubljana, Faculty of Medicine, Public Health Centre, Zaloška 4, 1000 Ljubljana, Slovenia.
authors.forename: Lijana
authors.initials: L
authors.lastname: Zaletel-Kragelj
keywords: qualitative research; social environment; social network analysis; social support