Reducing teen smoking in Chile

A national tobacco prevention campaign launched in 2006 in Chile that banned smoking at high schools and sale of tobacco near school grounds helped dramatically reduce smoking among adolescents, and was particularly effective in discouraging young teens from starting to smoke, according to a new study by Harvard T.H. Chan School of Public Health researchers and colleagues.

The researchers gathered longitudinal repeated cross-sectional time series data for 319,798 Chileans observed between the years 2000 and 2011 from nationally representative data on self-reported smoking behavior. They compared before- and after trends in smoking behavior in the teenage vs. the university-aged control group. Based on this analysis, they observed a 2.9% greater annual decline in smoking prevalence in the target group than in the control group after the implementation of the law. “We estimated that by 2011, the teenage smoking rate in Chile was 13.7% lower than it would have been without the ban. This is a dramatic decrease considering about 40% of teenagers in Chile smoked prior to the ban.” said lead author Andrea Feigl, ScD ’15, a visiting scientist in the Department of Global Health and Population, and scientist at Abt Associates.

Eighth and ninth graders were found to be the groups in which the smoking ban had the greatest smoking decline. “This demonstrated that the smoking intervention was most effective at prevention in early adolescence rather than late adolescence,” said co-author Eric Ding, research faculty in the Department of Nutrition.

However, the ban did little to lower smoking frequency among students who already smoked regularly. This indicates more smoking cessation programs are needed to help teens who are already regular smokers to quit.

This unique impact evaluation study, published online July 28, 2015 in the WHO Bulletin, is among the first ever long-term nationally representative study of this kind in the world, investigating the effects of a national health program.

Other Harvard Chan School authors include Joshua Salomon, professor of global health, and Goodarz Danaei, assistant professor of global health. Senior author was Esteban Calvo, MPH’10, associate professor of the Universidad Diego Portales, Santiago, Chile, and adjunct assistant professor at Columbia University.

Read the paper: Teenage smoking behaviour following a high-school smoking ban in Chile: interrupted time-series analysis

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