In 2012, Thomas Wills walked into a high school in Hawaii to distribute surveys and was surprised to find students vaping in class. Back then, he said, only a handful of students were smoking electronic cigarettes — a year later, nearly 30 percent of Hawaii high school students had tried them at least once.
That reflects a broader national trend: a 2014 survey by the Centers for Disease Control and Prevention reported that 2 million high school students used e-cigarettes at least once in the prior month. But that trend might have a worrisome corollary. Teens who start with e-cigarettes are more likely to later smoke cigarettes, Wills’s group has found.
In the study, Wills followed more than 2,000 Hawaiian high school students for a year. Teens who had never used e-cigarettes at the beginning of the study had a 5 percent likelihood of becoming smokers a year later; that likelihood rose to 10 to 20 percent for those who smoked e-cigarettes at the beginning. And more frequent use of e-cigarettes was associated with a higher likelihood of smoking later. Wills found that correlation held true even after he controlled for factors like age, gender, parental education, and rebelliousness. The findings were published Monday in the BMJ.
The research confirms the results of earlier studies which have found that e-cigarette use correlates with subsequent cigarette smoking among adolescents. One caveat, however: some individuals who started smoking e-cigarettes might have become smokers later anyway, regardless of their e-cigarette usage. But Wills said that controlling for information about students’ demographics, personality, and upbringing, which he did, should mitigate that effect.
Many of the health impacts of e-cigarettes are not well understood. That has led pediatricians to call for laws against e-cigarette sales to minors.
But e-cigarettes can have benefits too, said Dr. Brian Primack, a professor and clinician at the University of Pittsburgh not involved with this study.
“I certainly see adults who are able to cut down on the number of cigarettes they smoke because of e-cigarettes,” Primack said. “In a lot of ways we have to be able to celebrate that and encourage that. On the other hand, I’ve also seen in my clinical practice a lot of people who start to use e-cigarettes to try to stop smoking, and they end up just smoking more.”
The next step for Wills’s group is answering the question of why students who vape are more likely to become smokers. He said that he has some preliminary results that show that e-cigarette use produces positive attitudes toward smoking, which he will be presenting at a conference next year.