Is obesity contagious

Transcript

2. Social influence:
3. Social A. Cohesion B. Support C. Modeling D. Capital E. Norms F. Stratification G. Learning H. Diffusion I. All of the above Contagion ?
4. : A person’s chances of becoming obese increased by 57% (95% confidence interval (CI) 6-123) if he or she had a friend who became obese in a given interval. “   “  
5. Epi battles Timeline 2007 Cohen-cole and fletcher Trogdon Christakis and Fowler Yakusheva Lyons 2008 2011
6. LET’S Explain social transmission homophily environmental confounding
7. & Discuss / critique THE social network literature
8. Game plan 1:15 – 1:45 exercise I & group discussion 1:45 – 2:30 exercise 11 & group discussion 2:30 – 2:40 Break 2:40 – 3:10 exercise 111 & group discussion 3:10 – 3:40 Decision: is obesity contagious? Implications discussion Wrap up & final thoughts 3:40 – 3;50 introduction to Gene-Environment Interactions
9. Group exercise 1 In pairs Consider & report back 1) How were the outcome and exposure defined and measured in your study? 2) How was the study population/ network defined? The Data  
10. 1t is always necessary to decide which measures are theoretically and empirically important for the subject under investigation Scott, social network analysis   “   “  
11. Group exercise ii In pairs Consider & report back 1) How did the authors address homophily and shared environment? (Were they successful?) 2) How was contagion measured? Methods  
12. http://biostatisticsryangoslingreturns.tumblr.com/
13. Group exercise iii In pairs Consider & report back 1)  Do you think that the authors’ conclusions were valid and supported by their results? 2)  Does your paper show that obesity is contagious? Interpretation  
14. Methods  
15. So…Is obesity Contagious?
16. IMPLICATIONS ADAPTED FROM NEW YORK CITY TIPS AND EDIQUITE BY NATHAN W. PYLE http://www.amazon.com/Basic-Tips-Etiquette-Nathan-Pyle/dp/0062303112
17. INTERVENTIONS ADAPTED FROM NEW YORK CITY TIPS AND EDIQUITE BY NATHAN W. PYLE http://www.amazon.com/Basic-Tips-Etiquette-Nathan-Pyle/dp/0062303112
18. Side note
19. A few extra Rabbit holes (Surely you do extra epi reading in your free time) Noel H & Nyhan b. The “unfriending” problem: The consequences of homophily in friendship retention for causal estimates of social influence. Social networks, 33: 3:211-218. 2011. Gelman A. Controversy over the Christakis-Fowler findings on the contagion of obesity. At http:// andrewgelman.com/2011/06/10/controversy_ove_2/ El-sayed, am, seeman l, scarborough p, galea s. Are network-based interventions a useful antiobesity strategy? American journal of epidemiology, 178:2 287-295. 2013.
20. A few extra Rabbit holes (Surely you do extra epi reading in your free time) Christakis NA, Fowler JH: Social network targeting to maximise population behaviour change: a cluster randomised controlled trial. Lancet 386:9989, 2007. VanderWeele TJ. Sensitivity analysis for contagion effects in social networks. Sociological Methods and Research, 40:240-255. 2011. VanderWeele TJ, Ogburn EL and Tchetgen EJ. Why and when" flawed" social network analyses still yield valid tests of no contagion. Statistics, politics, and policy 3.1 2012.
21. Thanks! Natalie Stennis: nsl2110@cumc.columbia.edu Emilie Bruzelius: eb2674@cumc.columbia.edu
22. Bonus - Other Considerations 1)  What statistical approach did the authors use? 2)  What are the strengths/limitations of the approach that they chose? 3)  How would you redesign the analysis to account for any weaknesses you note? stats