Definitions and Measurement

Social network is defined as "the web of social relationships that surround an individual" (Berkman and Glass, 2000). An important distinction that is drawn between the concepts of social networks versus social support is while that the former term refers to the structure of social ties, the latter refers to their functional aspects (such as the exchange of information, instrumental aid, and affection).1 Social networks can be further characterized according to their size (number of members connected to the index individual), frequency of contact, and the diversity of domains in which the individual maintains social relations (e.g., marital ties, friendships, voluntary groups, and church membership).

Broadly speaking, two approaches exist by which to measure social networks: (a) the egocentric network assessment approach, which inquires about the extent of an individual's (the

Department of Society, Human Development and Health, Harvard School of Public Health, 677 Huntington Avenue, Kresge Building 7th Floor, Boston, MA 02115, USA e-mail: [email protected]

1Medical students are familiar with the distinction between structure and function. For example, the structure of the cardiovascular system consists of a central pump (the heart) and some pipes (arteries, veins), while the function of the system is to convey oxygen to tissues.

ego's) social ties (e.g., "Are you married?", and "How many close friends do you have?") and (b) the sociometric (or whole social network) approach which attempts to measure the totality of social connections within a structure. For reasons of practicality, most epidemiologic research has focused on the egocentric network approach. In large-scale epidemiological studies, the typically adopted approach has been to include a few brief items on a survey inquiring about a respondent's social ties (size, frequency, and diversity of domains), and then following the individuals over time to observe the incidence of health outcomes (morbidity and mortality). For example, the widely used Berkman-Syme Social Network Index (1979) consists of just seven items inquiring about marital status, number and frequency of contact with children, number and frequency of contact with close friends, and membership in voluntary organizations and church groups. The virtues of this approach consist of its brevity as well as proven ability to predict future health outcomes.

By contrast, the sociometric approach is far more demanding, since the method requires that every person nominated by the ego as a personal contact (the alters) must in turn be approached in order to map the entire social network. Sociometric approaches are most useful when examining network structures with clearly defined boundaries, and for that reason they tend to be used in examining phenomena such as the spread of high-risk behaviors in networks of injection drug users (Friedman and Aral, 2001) or the spread of suicidal ideation in school settings (Bearman and Moody, 2004).

A. Steptoe (ed.), Handbook of Behavioral Medicine, DOI 10.1007/978-0-387-09488-5_18, © Springer Science+Business Media, LLC 2010

0 0

Post a comment