The effects of social networks on tobacco use among high-school adolescents in Mexico / Efectos de redes sociales sobre el uso de tabaco en adolescentes de preparatoria en México

OBJECTIVE: To identify the effect of centrality in social network positions on tobacco-use among high-school adolescents in Tonala, Jalisco, Mexico. MATERIALS AND METHODS: Longitudinal sociometric social network data were collected among 486 high-school adolescents in 2003 and 399 in 2004. The survey included: social network components, smoking and sociodemographic characteristics. Social network measures of centrality were calculated and multivariate logistic regression was used. RESULTS: Ever used tobacco (OR= 44.98), marginalized-low stratum (OR= 2.16) and in-degree (OR=1.10) predicted tobacco use. Out-degree (OR= 0 .89) and out-in-degree (OR= 0.90) protected against tobacco use. CONCLUSION: Nominating more friends rather than receiving such nominations was protective for tobacco use. Popular students, those receiving many nominations, were at higher risk for tobacco use. Involvement of leaders with capacity to influence might be an efficient strategy for dissemination of preventive messages.

OBJETIVO: Identificar el efecto de posiciones de centralidad de la red social sobre el uso de tabaco en adolescentes de preparatoria en Tonalá, Jalisco. MATERIAL Y MÉTODOS: Estudio longitudinal de redes sociales sociométricas. Participaron 486 bachilleres (2003) y 399 (2004). La encuesta incluyó: componentes de redes sociales, tabaquismo y características sociodemográficas. Se calcularon medidas de centralidad de redes sociales y utilizó regresión logística multivariada. RESULTADOS: El consumo alguna vez de tabaco (RM= 44.98), estrato socioeconómico marginado-bajo (RM= 2.16) y vínculos recibidos (RM=1.10) predijeron el tabaquismo; mientras que los vínculos enviados (RM= 0.89) y la diferencia entre vínculos enviados y recibidos (RM= 0.90) protegieron contra el tabaquismo. CONCLUSIÓN: Nombrar más amigos que ser nombrado por otros protegió contra el tabaquismo. Los estudiantes populares, aquellos con muchos nombramientos, tuvieron mayor riesgo de ser consumidores. La inclusión de líderes con influencia podría ser una estrategia eficiente en la diseminación de mensajes preventivos.

Promoting breastfeeding in Bolivia: do social networks add to the predictive value of traditional socioeconomic characteristics?

This study tested whether the prediction of health-related knowledge (correct breastfeeding practices in this case) could be improved by including information about the composition of an individual's personal network above and beyond that predicted by his/her socioeconomic or demographic characteristics. Few studies have tested the predictive value of social networks, especially for population-based studies, despite an increased use of social networks in the past few years in several fields of health research, especially in research relating to prevention of HIV/AIDS and design of HIV/AIDS programmes. Promotion of breastfeeding practices that enhance child survival is important in Bolivia because of high infant morbidity and mortality in the country. Data on a cross-sectional urban probability sample of 2,354 women and men aged 15-49 years were collected from seven urban areas in Bolivia. Model building and the log likelihood ratio criteria were used for assessing the significance of variables in a logistic model. Results showed that the network variables added significantly (p < 0.05 for knowledge of breastfeeding only with no other liquids and for knowledge of breastfeeding only with no solids p < 0.01) to the predictive power of the socioeconomic variables. These results may also hold for other health research areas, increasingly using social network analysis, such as that of HIV/AIDS.

Condom use and migration in a sample of Mexican migrants: potential for HIV/STI transmission

OBJETIVO: Analizar la asociación entre el uso del condón y la migración a Estados Unidos en dos municipios mexicanos. MATERIAL Y MÉTODOS: Estudio transversal no probabilístico de redes sociales egocéntricas. Muestra de 354 migrantes. Cuestionario sobre prácticas y redes sexuales, historia de ITS y migración. Análisis mediante regresiones logísticas. RESULTADOS: La mayor experiencia migratoria se asoció significativamente al uso consistente del condón en Tonalá (RM: 4.12; p<.05) y Cuauhtémoc (RM: 3.87; p< .05). Otros predictores fueron: edad, tipo de pareja y percepción de la fidelidad. CONCLUSIÓN: Los datos apoyan la hipótesis de la asociación entre la migración y el uso del condón.