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Detecting implausible social network effects in acne, height, and headaches: longitudinal analysis.
Ethan Cohen-Cole1, Jason M Fletcher
1Federal Reserve Bank of Boston, 600 Atlantic Avenue, Boston, MA 02210, USA.
BMJ (Clinical Research Ed.)
|December 6, 2008
Summary
Social network effects on health outcomes like acne, headaches, and height are not significant when environmental factors are properly controlled. Researchers should be cautious attributing correlations to network phenomena.
Area of Science:
- Social epidemiology
- Adolescent health
- Statistical modeling
Background:
- Social network analysis is increasingly used to study health behaviors and outcomes.
- Previous studies often show correlations between friends' health statuses, but may not adequately control for shared environmental factors.
Purpose of the Study:
- To determine if "network effects" are detectable for health outcomes not typically associated with social contagion.
- To assess the impact of controlling for environmental confounders on observed network effects in adolescent health.
Main Methods:
- Longitudinal data from the National Longitudinal Study of Adolescent Health (Add Health) were analyzed.
- Statistical methods, including logistic regression, were used to examine associations between friends' health outcomes and individual outcomes.
- Analyses controlled for individual's and friend's lagged health status and environmental confounders.
Main Results:
- Initial analyses suggested significant network effects for acne, headaches, and height.
- A friend's acne or headaches showed a trend towards increasing an individual's risk.
- However, after adjusting for environmental confounders, these network effects became insignificant.
Conclusions:
- Observed correlations in health outcomes between friends may not represent true social network effects.
- Environmental factors play a crucial role and must be adequately controlled for in network health studies.
- Caution is advised when attributing health outcome similarities solely to social network phenomena.
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