Second , we show that network composition , individual network central ity , and network structure are associated with important health behaviors and health and development outcomes in different context s across multiple levels of analysis and across distinct network types .
Lastly , we highlight the opportunities for health research ers and practitioners in LMICs to 1 ) design effective studies and interventions in LMICs that account for the sociocentric network positions of certain individuals and overall network structure , 2 ) measure the spread of outcomes or intervention externalities , and 3 ) enhance the effectiveness and efficiency of aid based on knowledge of social structure .
In low- and middle-income countries ( LMICs ) , naturally occurring social networks may be particularly vital to health outcomes as extended webs of social ties often are the principal source of various re sources .
Longitudinal analysis of large social networks: Estimating the effect of health traits on changes in friendship ties
We develop novel mixed effects models to examine the role of health traits on the status of peoples ' close friendship nominations in the Framingham Heart Study . The health traits considered are both mutable ( body mass index ( BMI ) , smoking , blood pressure , body proportion , muscularity , and depression ) and , for comparison , basically immutable ( height , birth order , personality type , only child , and h and edness ) ; and the traits have varying degrees of observability . We test the hypotheses that existing ties ( i.e. close friendship nominations ) are more likely to dissolve between people with dissimilar ( mutable and observable ) health traits whereas new ties are more likely to form between those with similar ( mutable and observable ) traits while controlling for persons ' age , gender , geographic separation , and education . The mixed effects models contain r and om effects for both the nominator ( ego ) and nominated ( alter ) persons in a tie to account for the fact that people were involved in multiple relationships and contributed observations at multiple exams . Results for BMI support the hypotheses that people of similar BMI are less likely to dissolve existing ties and more likely to form ties , while smoker to non-smoker ties were the least likely to dissolve and smoker to smoker ties were the most likely to form . We also vali date d previously known findings regarding homophily on age and gender , and found evidence that homophily also depends upon geographic separation . Copyright © 2011 John Wiley & Sons ,
Second , we show that network composition , individual network central ity , and network structure are associated with important health behaviors and health and development outcomes in different context s across multiple levels of analysis and across distinct network types .
Lastly , we highlight the opportunities for health research ers and practitioners in LMICs to 1 ) design effective studies and interventions in LMICs that account for the sociocentric network positions of certain individuals and overall network structure , 2 ) measure the spread of outcomes or intervention externalities , and 3 ) enhance the effectiveness and efficiency of aid based on knowledge of social structure .
In low- and middle-income countries ( LMICs ) , naturally occurring social networks may be particularly vital to health outcomes as extended webs of social ties often are the principal source of various re sources .