Laboratory for the Study of Stress, Immunity, and Disease

Scoring the Social Network Index

MEASURES

• Number of High-Contact Roles (Network Diversity)
• Number of People in Social Network
• Number of Embedded Networks

Number of High-Contact Roles (Network Diversity) 

Definition: This is the number of social roles in which the respondent has regular contact (i.e., at least once every 2 weeks) with at least one person.  The maximum number of high-contact roles is 12.   They are: spouse, parent, child, child-in-law, close relative, close friend, church/temple member, student, employee, neighbor, volunteer, and group member.  (It would also be possible to count each group a person belongs to [question 12] as a separate social role, however we have not done this in our previous work.) 

Computation:  For each of the 12 possible high-contact roles, assign a 0 if the respondent does not have the role and a 1 if he/she does.  The total number of high-contact roles is computed by summing the 0s and 1s.  The table below shows which scale items are used in the computation and how each is scored. 
 

Number of People in Social Network

Definition:  This is the total number of people with whom the respondent has regular contact (i.e., at least once every 2 weeks). 

Computation:  For each of the 12 possible roles, determine the number of people with whom the respondent has regular contact.  The total number of people in the social network is computed by summing across the 12 roles.  The table below shows which scale items are used in the computation and how each is scored.

NOTE: In our experience, individuals sometimes interpret the SNI item inquiring about the number of "other group" members with whom they interact at least once every 2 weeks more broadly than we intended, with some respondents reporting up to 100 or more fellow group-members. To ensure that social network size scores are not artificially inflated by individuals reporting large group memberships, we recommend recoding the variable so that all values over 6 are given a score of 7, thus keeping it consistent with all other quantitative SNI items.

Number of Embedded Networks

Definition:   This measure is meant to reflect the number of different network domains in which a respondent is active.  The maximum possible is 8.  They are: family, friends, church/temple, school, work,  neighbors, volunteering, and groups.  To receive a point for a domain, a respondent must have at least 4 high-contact people within that domain.  The 5 family roles are collapsed into one network for this measure.  To receive a point for family, they are required to have at least 3 high-contact family roles as well as 4 high-contact people. 

Computation: If the subject meets the criteria for an embedded network, assign a score of 1 for that network, otherwise assign a 0.  The total number of embedded networks is computed by summing the 0s and 1s.  The table below shows the criteria used for each embedded network. 
 

Although we have found this useful in a number of exploratory analyses, we have not published any data using number of embedded networks. 
 

Reference:   Cohen S, Doyle WJ, Skoner DP, Rabin BS, Gwaltney JM (1997).  Social ties and susceptibility to the common cold.  JAMA, 277, 1940-4. Link to full-text (pdf)
  
  Version: July 23, 2014