Adolescents who started using tobacco with noncigarette products were more likely to have smoked conventional cigarettes within one year than young people who had never used tobacco.
"Although e-cigarettes are the most common form of non-cigarette tobacco used by youths (exceeding cigarette use), any use of all forms of non-cigarette tobacco was independently associated with greater risk of future cigarette smoking; risk was greatest with use of multiple products, a use pattern that is increasing among youths", the researchers wrote.
About 90 percent of adult smokers first tried cigarettes by the time they turned 18, according to the study. Previous studies have demonstrated associations of use of individual products such as e-cigarettes, smokeless tobacco, and hookahs with future cigarette smoking. This may have weakened some connections between cigarette smoking and other tobacco products, the authors note. The research is based on data from the participants of the nationally representative Population Assessment of Tobacco and Health (PATH) study.
The success rate for people who used e-cigarettes was 40 percent lower than the rate for people who did not use the products, the study found.
No more using e-cigarettes - or "vaping" - on school grounds, say UT Health San Antonio officials. When re-interviewed one year later, 4.6 percent of the group reported that they had now smoked a cigarette.
Despite the large size of the study population, one limitation is the relatively small number of tobacco product users by year end, particularly the 2 percent of youth who admitted sampling one or more of these items in the past month.
The study is believed to be the first to analyze all non-cigarette tobacco products.
"Products like e cigarettes are essentially gateways to smoking cigarettes", Chandler said.
People who have a tendency to experiment with tobacco products in general, are also more likely to also experiment with cigarettes.
They added that the study has direct implications for regulatory policy aimed at preventing youth smoking. "The estimated health risks of non-cigarette tobacco products should include the addition health consequences of future cigarette use".
"I'm perhaps surprised about how similar the relationships were for each product across the board", Watkins said.
Funding for this research was provided by the U.S. National Cancer Institute and FDA Center for Tobacco Products, the National Institute on Drug Abuse, and the National Center for Advancing Translational Sciences.
Initially, about 78 percent of the respondents had never used tobacco products, 77 percent said they accessed the Internet at least once per day, and 63 percent used a social network at least once per day.