(CNN) - A new study has found that teens who start using e-cigarettes are four times more likely to start smoking conventional cigarettes a year later.
That was true even if they never intended to start smoking.
The study was published Monday in the medical journal Pediatrics.
Researchers say the findings suggest e-cigarette use facilitates cigarette smoking primarily among tobacco-naive adolescents with no previous smoking intentions.
The study also says doctors can use the data to intervene before their young patients start vaping.